The point is, only God is to judge. We lock people up or execute them if the are an immediate threat but we let sinners keep on sinning most of the time. It's part of the whole free will thing. Our job is to get them on the right path, not to kill them.
This is a popular but incorrect understanding. Those who favor relativism and non-judgementalism love to quote Matthew 7:1, but fail to read though verse 5. These verses deal with hypocrisy. Verse 5 says "You hypocrit, first take the log out of your own eye, and THEN you will see clearly to take the speck out of your brother's eye."
We can judge, but we must do so while not engaging in disqualifying behaviors.
"The point is, only God is to judge. "
The Bible command us repeatedly to judge righteously - not hypocritically. The "Judge not" is part of the false doctrine of apostate church's like Rick Warren's Saddleback church.