Paul and Jesus seem to say the same thing about passing judgment on others (besides just "don't do it"). Jesus says, "Judge not and you will not be judged." Paul says the same thing, but from the opposite direction: "Judge not, because you are doing the same things yourself."
This has been a hard passage for me to understand. In the letter to the Romans, he lists some pretty nasty vices. I would find it hard to believe that the Jewish Christians he was especially addressing were guilty of all that (could people who suffered scruples over dietary laws feel free to do things like robbing temples?). So what did he mean? In another context, Paul completely rejects judgments being passed on him. He says he won't even pass judgment on himself: all judgment belongs to God.
Jesus tells us how to avoid entering a world where judgments fly back and forth.
Is it possible that Paul is hinting at how superficial we are when we presume to pass judgment on one another, and so our judgment turns back on us?