Jesus’ statement, “judge not, that you be not judged,” (Mt. 7:1) is one of his most memorable sayings. But it is usually remembered by those who think Jesus was never judgmental. Jesus, however, is here warning disciples again (as in Mt. 5:21-26) about not condemning one’s brother or sister, one’s fellow disciple–in this case, because of a mere “speck.”
If a disciple sees a “speck” (a small sin) in a brother’s or sister’s eye, and condemns that fellow disciple, then the disciple judging has a “log” (a big sin) in his own eye. Such condemnation will result in his own judgment (from God). In 5:22 Jesus said a disciple who calls a brother a “fool” (that is, condemns a brother as someone who is not part of the family of God) is in danger of the judgment of hell.
Jesus calls the judging disciple (with the “log”) a hypocrite, associating him with the hypocrites (scribes and Pharisees) in the synagogues. Later (in Mt. 23:23) Jesus will strongly judge such hypocrites: they make “mountains out of (small) molehills;” they overvalue specks like tithing the smallest garden plants while neglecting weightier matters like justice, mercy, and faith. This is like straining out a gnat and swallowing a camel (see 23:24). These hypocrites (“actors”) perform dramatic scenes of denunciation, based on a speck of evidence.
In the early churches, minor issues like eating certain foods, celebrating certain days, or performing circumcisions led some Christians to condemn others (for example, see Acts 15:1-5, Rom. 14, and Col. 2:16-17). Of course more modern churches have similarly condemned other churches because of minor issues such as details about the best mode of baptism or the proper way to celebrate the Lord’s Supper. The obsession with such specks also overlooks Jesus’ judgments against the significant injustice/unrighteousness of those like the scribes and Pharisees: for example, they use public gifts to the poor for their own self-glory (see Mt. 6:1-2), and show no mercy to Jesus when he compassionately feeds poor disciples or heals the sick on the sabbath (Mt. 12:1-14).