Should Christians judge others’ behavior?

The Bible offers two seemingly contradictory commands regarding judgment. Jesus strictly forbids self-righteous, hypocritical judgment of the heart ("Do not judge, so that you will not be judged" - Matthew 7:1), which is reserved for God alone. However, He and the apostles mandate wise, discerning judgment of actions and teachings within the church ("Test everything; hold fast to what is good" - 1 Thessalonians 5:21). A Christian must never judge a person's worth or salvation, but is required to discern behavior and doctrines, especially within the Christian community, to uphold biblical standards.