How many times have we, as Christians, heard this passage from Matthew 7:1? Usually it is because someone feels we have unfairly judged some one, often by saying they are not an actual Christian. Just as often, those who like to throw this verse at us have somehow neglected to read the entire passage, which continues through verse 5. If they had they may realize they have misused it. Taking this passage out of context is still a favorite past time of those who enjoy criticizing Christians. A variation of this occurred recently when I was taken to task for saying Muslims, Mormons, and Jehovah's Witnesses were not Christians, and would, unless they changed their ways, suffer eternal damnation in hell.
The statement was made to me that we cannot say if another person is saved or not. In fact, the person I was talking to went on to say, that includes Muslims, Mormons, Jehovah's Witnesses, etc. And the reason we cannot say, I was told, is because only God knows a persons heart. We cannot know a person's heart, and if we presume to make a judgment against them by saying they are not saved, then we are placing ourselves in the Lord's place, when only He has the ability and the right to say whether or not someone is saved. In fact, they went on to say, not even the Apostle Paul would dare to judge whether or not someone was saved.

Now, I realize the person I was conversing with is trying to be loving, and tolerant, and, possibly, politically correct; and I have to admit they put forth a reasonable argument. As reasonable as it may have been, however, it was also not entirely true. While only the Lord will determine who enters heaven and who does not, the Scripture tells us that yes, in fact, we can know a person's heart – at least to some extent, and enough to know if a person is saved or not. And, in fact, to refute the person I was speaking with, Paul actually does make a judgment call as to who is and who is not saved; and, so does the Apostle John.

According to God's Word, as recorded by the Apostles Paul and John, the following people will not enter heaven, and will spend eternity in hell:

1. (from Romans 8:5-8,13) Those who live according to the flesh and set their minds on the things of the flesh, those who are carnally minded. They live in enmity against God, and cannot please Him.

2. (from 1 Corinthians 6:9-10) The unrighteous, fornicators, idolaters, adulterers, homosexuals, sodomites, thieves, those who are covetous, drunkards, revilers, extortioners;

3. (from Galatians 5:19-21) Adulterers, fornicators, those who are unclean, those who are lewd, idolaters, sorcerers, those who harbor hate, those who are contentious, those who harbor jealousy, those who engage in outbursts of wrath, those who follow selfish ambitions, those who cause dissensions, those who promote heresies, those who are persistently envious, murderers, drunkards, those who engage in sexual orgies, and the like;

4. (from Ephesians 5:5) Fornicators, unclean persons, covetous persons/idolaters;

5. (from 1 Timothy 1:9) The lawless and insubordinate, the ungodly, unrepentant sinners, the unholy, the profane, murderers and manslayers;

6. (from Hebrews 12:14) Those who do not pursue peace, the unholy;

7. (from Revelation 22:15) Sorcerers, the sexually immoral, murderers, idolaters, and those who practice deceit and lying.

There is a further condition that applies to each of these 37 groups of people; and this condition is explained by both Paul and John. That additional condition is habitual persistence. Those who commit these sins are still eligible for salvation if they repent of their sins, confess their sins to God, and seek forgiveness of their sins through Him in Christ. Those who continually live lives that are patterned by persistent, habitual unrepentant sin, will die in their sin and they face eternal damnation in hell.

Paul adds this additional condition of persistence in Galatians 5:19-21 where, after listing numerous sins that the commission of such are just grounds for eternal punishment, states, “those who practice such things will not inherit the Kingdom of God.” His use of the word “practice” indicates the habitual, persistent unrepentant sin that results in eternal damnation. The Apostle John speaks of this in 1 John 3:7-9, where he writes, “Little children, make sure no one deceives you; the one who practices righteousness is righteous, just as He is righteous; the one who practices sin is of the devil; for the devil has sinned from the beginning. The Son of God appeared for this purpose, to destroy the works of the devil. No one who is born of God practices sin, because His seed abides in him; and he cannot sin, because he is born of God.” (NASB)

It is clear by these passages that those who live lives patterned by the persistent, habitual unrepentant practice of sin are destined for hell. It is not being judgmental to say these things, it is simply stating a truthful fact as recorded in Scripture. And pointing out to a person who happens to be in one of these 37 categories of people bound for hell, that they are, in fact, bound for hell, is not placing oneself in the role of Judge, nor taking the place of Jesus. It is simply stating an obvious fact for the purpose of explaining the gospel of Jesus Christ to them. If one does not explain to them why they need salvation, then they have no reason to believe or even question their need for salvation. Refusing to expose their sin (and always in a loving and respectful manner, with the singular goal of causing them to understand their sin and their need for the Savior Jesus Christ), and simply telling them, “God loves you and you need to come to Christ for salvation” is presenting only half a gospel; and it is doing them a disservice. An unloving disservice at that.

Atheist Penn Jillette once said (and I think his words illustrate this point beautifully),

I would add to his words by saying, “How much do you have to hate someone to not explain to them in loving and respectful, but clear and unmistakable terms, the spiritual danger they are in and why (since they clearly don't see it as a danger) their current lifestyle is spiritually deadly.
Of course, all of this serves only to tell us that there are people who are going to hell. It may be politically incorrect to say this, and it may cause people a fair amount of discomfort to hear it (as well as say it, which is why many avoid saying it), but it is an undeniable fact; and as Christians we cannot simply shuffle along through life with our head down, trying to remain unnoticed as we fly under the radar of society while people blithely skip merrily down the well-lit and alluring highway to hell. We have a moral responsibility given us by God Himself (see Matthew 28:18-20) to do everything we can to ensure they have every opportunity to get off that highway and onto the narrow path. As Charles Spurgeon, the great 19th century preacher, once said,

In answer to the person I told you about at the beginning of this post, who said, “only God knows a persons heart. We cannot know a person's heart, and if we presume to make a judgment against them by saying they are not saved, then we are placing ourselves in the Lord's place” I say, not true! Scripture tells us very clearly that we can know all about a persons heart, at least to a degree. We know that the heart is “deceitful above all thing and desperately wicked” (Jeremiah 17:9), which is why those who find themselves in the categories listed above do not feel they are in any danger. Their hearts are telling them everything is fine! There's nothing to worry about! It's all good! They are “darkened in their understanding, alienated from the life of God because of the ignorance that is in them, due to their hardness of heart.” (Ephesians 4:18). This is why even we are warned to “keep our hearts with all vigilance, for from it flow the springs of life.” (Proverbs 4:23)
Jesus tells us in Matthew 12:34; 15:18-20 and Mark 7:21, that it is out of the abundance of the heart that the mouth speaks. In other words, it is your heart that controls who you are, how you speak, how you act and how you think; and with the unregenerate it is painfully clear who they are. Look at the 37 groups of people above. They are living those lifestyles in an unrepentant, habitual and persistent manner because that is what their hearts are set on, and they are at enmity with God. To say we cannot know their hearts is nonsense! Of course we can! All we have to do is examine their lives! And do not think they may simply be “carnal Christians,” for there is no such thing! The belief that there are is a belief that was born in hell itself. One cannot live a life of carnality and still be a Christian. To live a carnal life is to live in enmity against God. Learn that. Remember that. And do not simply apply it to the lives of others, but apply it to your own life as well!

Scripture also gives us additional indicators as to the condition of someone's heart (or your own heart). As Jesus said, “out of the heart come evil thoughts, murder, adultery, sexual immorality, theft, false witness, slander.” (Matthew 15:18-20) The heart is where these things are born, where they take root and grow from sinful thoughts into sinful actions; and understand that sinful thoughts which are not excised immediately through prayer as just as condemning as sinful actions (Matthew 5:21-48).

Yes, it is true that God knows our hearts. Scripture makes that abundantly clear in passages such as Luke 16:15; Acts 15:8; Proverbs 21:2; Jeremiah 17:10; 1 Thessalonians 2:4; Jeremiah 12:3; Revelation 2:23; Romans 8:27; and more. But we too can know their hearts, to a certain degree, as well. Just as we can know the heart of an unregenerate person by the way they act, speak, live, etc., we can also know the heart of a true believer because Scripture also gives several indicators of a regenerate heart. The true believer will not lift up his soul to what is false, and will not swear deceitfully (Psalm 24:4). The heart of a true believer will trust in the Lord and not be afraid of difficult times (Psalm 27:3; 112:7). The heart of a true believer will produce speech that is gracious (Proverbs 22:11). The heart of a true believer will long for the Lord (Psalm 84:2), will create brotherly love and obedience to the truth of Scripture (1 Peter 1:22). It will create joy and cheerfulness in the true believer (Proverbs 15:13-15); because the heart of the true believer honors Christ the Lord as holy, and the abundant good treasure that is stored up within the heart of the true believer will always bring forth abundant good (1 Peter 3:15; Luke 6:45). That is how we can know with a reasonable degree of certainty, who is and who is not a true believer.

Just as important as all of this is, there is something that is even more important. Vitally important, even, and something that every true believer must – absolutely must – remember, and never, ever forget. First, go back to the beginning of this post and re-read all of those 37 categories of horrible, depraved, and disgusting sin. Go ahead, I'll wait. Good. Have you re-read them? Now remember this, those categories describe us as well. Not how we are now, but we once were; but, as Paul writes, we “were washed, [we] were sanctified, [we] were justified in the name of the Lord Jesus Christ and in the Spirit of our God.” (1 Corinthians 6:11) Those categories were what we were wallowing in when Jesus called us out of the horrible mire of sin, and changed our hearts – cleansed our hearts; because He can do that you know. It's what He does.

Our Lord, through the prophets Ezekiel and Jeremiah, tells us just what He does with unbelievers whom He calls to salvation. He says, “I will give them one heart, and a new spirit I will put within them. I will remove the heart of stone from the flesh and give them a heart of flesh, that they may walk in My statutes and keep my riles and obey them; and they shall be my people, and I will be their God.” (Ezekiel 11:19-21 cf. Jeremiah 32:40). While these promises were made to the Israelites, I believe they hold true for God's people today. God can and will regenerate the hearts of those He calls to Himself. The Apostle Paul points this out in Acts 15:9 when he states, regarding the salvation of the Jews and the Gentiles, that God “made no distinction between us and them, having cleansed their hearts by faith.” The people of God, whomever they are and from where ever they come, will have their hearts cleansed, “So that [Jesus] may establish your hearts blameless in holiness before our God and Father, at the coming of our Lord Jesus with all His saints.” (1 Thessalonians 3:13).

God can and does change hearts, but it is still our responsibility to engage and interact with the unregenerate unbelievers, and share the full and complete gospel with them (Matthew 28:19-20; Romans 10:14-15); and that includes recognizing who the unregenerate are, and explaining to them, again in love and with respect, why they need the Savior Jesus Christ, and how to come to Him.

Building a proper understanding of Scripture is a lot like building a fence. In fact, it is a lot like many projects one does around the home, garage or yard. But since I need a fence, I'll use that analogy.
What do I need to build my fence? I need four-by-fours, two-by-fours, and hog panels. This is a utilitarian fence, not an entry in Better Homes and Gardens. So I go to the store and purchase my supplies. I now have a stack of four-by-fours, two-by-fours, and hog panels; as well as a box of nails, some screws, and a box of fencing staples. In essence, I have a fence. It is not yet assembled, but I do have a fence. Now I need the proper tools: hammer, screw driver, and pliers (because you always need pliers), and I need a post hole digger. So I head to the shed and gather up my tools; and I need an accurately drawn up plan with proper measurements, etc. Once I have that, I mark off where the posts will go, sink the posts, attach the two-by-fours, and then put up the hog panels, and voila! I have an assembled fence.

However, the potential for disaster is never far away. Therefore, to avoid disaster I must do three things. They are:

1. I must have the proper tools (I can't pound staples and nails with a tape measure)
2. I must have at least a basic understanding of my tools and how they are properly used.
3. I must actually get up and do the work, otherwise I will simply have a pile of fence but not a properly assembled and useful fence.
“But how does this relate to theology?” you may ask. I know I would! To properly understand Scripture, and thus have a proper understanding of theology, one must follow the exact same steps. The fence is the Bible, and just as a properly built fence can protect your property; a properly understood Bible can protect you spiritually from a great many spiritual dangers, primarily the twin dangers of false doctrines and false teachers.

So, the first thing you have to do is gather up your supplies, namely, a Bible. And get a good one. There are many to choose from, some good (I like the NASB, NKJV, and ESV) and there are some bad ones, such as The New World Translation, the Joseph Smith Translation, and The Message. I won't go into all of the various factors that go into finding a good Bible, but try to stay with either a “word for word” translation or perhaps a “thought for thought” translation. But stay away from paraphrases, and this is important, stay away from study Bibles produced by individuals. At least for the time being. While there are some very very good ones, there are some very very bad ones. So until you are well grounded in Scripture, stay away from them.

Now you need your tools, and you need the proper tools to do the job. They are, in order of importance:

1. Prayer, prayer, and more prayer. Talk to the Lord and ask Him to help you to understand just what your are reading. Trust in the Holy Spirit to guide you in your studies, believe me, He will. But also understand, the vast majority of Scripture is self-explanatory. There are no “hidden” meanings, there are no “Bible codes,” and there is no need for extra or special revelation. Just read the Bible, and read it as you would any other book. There will be parts that are literal, parts that are figurative such as analogies, parts that are poetic, parts that are prophetic, and parts that are simply historical. And they are all obvious to the reader.
2. A basic understanding of biblical hermeneutics. A big word that simply means interpretation, or proper understanding. The basic rules of good biblical hermeneutics are:

A) The Bible interprets the Bible. You don't have to go to an outside source to interpret it for you.
B) The explicit passages interpret the implicit passages. If an implicit passages seems to contradict an explicit passage, understand that it doesn't really contradict. You are simply interpreting the implicit passage incorrectly.
C) Context is everything. To understand a particular passage of Scripture, look at the various contexts in which it is written. Look at the immediate context first. By this I mean the passages immediately before the passage, and those immediately after it. Next, look at the extended context. Do this by reading the entire chapter, and/or the entire book. Third, look at the cultural and historical context. What would the passage most obviously mean to someone from the same culture and time period within which it was written? Obviously this is going to take some dedication and some work. But just as with building a good sturdy fence, if you want something that will last and withstand attacks against it, you're going to have to work hard and do it properly.
D) And finally, understand that there are no contradictions (if you find one, read it again, and follow rules A-C); and there are no real errors. Yes, to be honest, you may find some minor textual variants, however, they are, as I said, minor, and they will not change the accuracy of any biblical doctrine.
3. You will need the proper tools. It is always helpful to have a knowledge of biblical Greek and Hebrew, but that is not always possible. Fortunately, there are a number of good reference works available – many online and free for download – that are available. First, a good word concordance, especially a Strong's or a Young's concordance. Both are geared for the King James Version, but that should not be a problem. It is also helpful to have at hand a good lexicon and/or expository dictionary. Two of the best are the Thayer's Greek Lexicon and the Vine's Expository Dictionary of Greek and Hebrew Words. A good Bible dictionary (such as the Holman's Bible Dictionary), a good Bible handbook (Unger's, Halley's, or Smith's), a good Bible encyclopedia (such as Nelson's) and possible a Bible Atlas (such as Moody's). All of these tools will help you to understand the original meaning of the various words found in Scripture, as well as the various customs, cultures, peoples, and lands of the Bible. This will aid you immensely in understanding the historical contexts of the Bible.

4. And last, you must actually pick up those tools and use them properly. You must pick up your Bible, and read it and study it daily, and do so properly if you want to be well grounded in it. Many people read their Bible through the focus of their own biases, their own preconceived ideas and presuppositions. Remember this final rule of proper Bible reading and studying. Write it down on the very first page of your Bible. Never forget it. And that final rule is: “Never change the meaning of Scripture to fit what you already believe, but rather, change what you believe to fit the Scripture.”

By understanding and following the basic outlines described in this article, you can have a strong, utilitarian, long lasting and protective fence; or you can have a strong, utilitarian, long lasting, and protective grasp of the Bible; or both!