"Judge not, lest ye be Judged..."
Today's Gospel (Luke 6:36-38) contains one of the most frequently quoted and also most frequently misunderstood Gospel passages of all. Jesus tells us:
Stop judging and you will not be judged. Stop condemning and you will not be condemned. Forgive and you will be forgiven.
This verse is often cited when Christians criticize some sort of behavior non-Christians approve of. To pick a contemporary issue, Christians point out the homosexual sex is a sin and they are quickly met with cries reminding us that Jesus taught us not to judge.
Not exactly.
Those interpreting this passage that way seem to have a claim to correctness on the face of it, but make a common mistake in the interpretation of Scripture: taking one verse out of context. The proper context is the entire Bible. (An another common example are those who mock Christians asking if we truly believe in the Bible, why don't we follow the Mosaic law and keep Kosher regulations. Because, in the Acts of the Apostles, we were freed from those restrictions which were meant to prepare for the coming of Christ. Now that he has come and given us a higher Law, we are free from almost all dietary restrictions.)
Getting back to the original topic, the Bible also tells us many time to admonish and correct those who have done wrong. How can we reconcile the verse quoted above with those?
The answer can be found in the final verse of today's Gospel:
For the measure with which you measure will in return be measured out to you.
We are not to judge the state of anyone's soul. That right (and duty) belongs solely to God. This final verse warns us that if we dare to say that someone is going to Hell for their actions, God will hold us accountable to the same standards we held them to. If we treat them with mercy and try to help them overcome their sins, God will judge us with mercy. As the Paul tells us in Galatians: "a person will reap only what he sows."
It's especially important to keep this in mind as frequently, the sins we hate most in others are those we are most liable to commit ourselves. Bishop Fulton Sheen wrote: "The way we judge others is very often the judgment which we pronounce on ourselves." People prone to sexual sins often most strongly condemn other who condemn others who commit sexual sins. Those who lie frequently are often liars themselves. We're most aware of certain sins because it's what we're used to doing ourselves.
Another thing to keep in mind to help yourself from attempting to judge people's souls is that while some sins are objectively wrong, God knows what drove a person to do that and that can mitigate a person's culpability. A sin that might be a grave and mortal sin for one person might not be so terrible when committed by another due to their circumstances. The action is still wrong, and we should gently point that out, but since only God knows the true state of a person's soul, we cannot dare to make that proclamation ourselves, lest God hold us to a standard we can't meet even though we hold others to it.
So, as the Christian motto often is put: "love the sinner, hate the sin." One way we show love for a sinner is to point out that they are, indeed, sinning. Now, if we wish to avoid driving further from Christ, we need to do it in a gentle manner that shows our love for them. But we need to do it. Sin destroys a person, and drives them from God, which is truly a fate worse than death. This is admonishing sinners is one of the spiritual works of mercy. It can save them from an unfortunate location in Eternity.
Above all else, do everything with love.

