I am willing to guess that Matthew 7:1 is the verse most quoted by not only those Christians who do not have as full of the knowledge of the Bible as they ought to have, but by the majority of those that do not know Christ. And though one can have a good conversation about most topics, rest assured that Matthew 7:1 is often injected into controversial topics that deal with “below-the-belt” sin, especially homosexuality. Most people will agree murder and stealing (two sinful practices that indicate that a person is not redeemed) are wrong but when it comes to the below-the-belt sins, a true Christian gets pelted with Matthew 7:1 when pointing out that these sins also indicate that those who practice such things shall not inherit Eternal Life.
The Greek for “judge” in Matthew 7 can mean a variety of things ranging from “selecting” to pronouncing an opinion or judgment and to “contend together.” When this occurs, the meaning of a word like this must be determined by its immediate context, its context within the given book, and its relationship to the entire Holy Bible. By doing this for the word “judge” in Matthew 7:1, we can soon see that it means to act as judge with powers of condemnation and without having proper knowledge.
Surely we can, and must, evaluate and then make a judgment call as directed by the Holy Spirit for we see in Matthew 7:15-20 Christ tells us we are to beware of false prophets, and we would be able to decide (judge in a way) by the fruits they bring forth.
When below-the-belt sin occurs within the Church, it is to be dealt with by the other Christians. After a church member had relations with his step-mother and the church did nothing about it, Paul wrote by the Holy Spirit (1 Corinthians 5 and 6) that the Corinthian church should have judge the man and administered discipline. By the Holy Spirit he writes (1 Corinthians 6:2-3), “Do ye not know that the saints shall judge the world? and if the world shall be judged by you, are ye unworthy to judge the smallest matters? Know ye not that we shall judge angels? how much more things that pertain to this life?”
Now if one reads at least chapter five they would see (5:12-13), “For what have I to do to judge them also that are without? do not ye judge them that are within? 13 But them that are without God judgeth. Therefore put away from among yourselves that wicked person.” One might readily point out that here it is indicated we should not judge the lost. However, if you look at the balance of the Scripture one can see in passages that refer to non-Christians that many of their sins are mentioned as damnable. Paul by the Holy Spirit listed a number of below-the-belt sins in 1 Corinthians 6:9 and stated by the Holy Spirit in verse 10 that such people would not inherit Eternal Life.
Was he judging? No. All Paul was doing was declaring the judgment already determined by God. Paul did not decide such people would not inherit Eternal Life, but God did.
It is the same when a true Christian by the Holy Spirit tells someone that something they are practicing is sin. Sometimes people really do not know we are all born sinners until it is shown to them from the Word of God. Having God deal with our sins is necessary for our salvation.
Knowing the Word of God and using it properly as directed by the Holy Spirit to state what God has already declared a sin is not judging, but a loving act of mercy on the part of the true servant of God who, like God, is “not willing that any should perish, but that all should come to repentance.” 2 Peter 3:9