What does the Bible say about self-examination for Christians?

In 2 Corinthians 13:5, Paul encourages believers to examine themselves to see whether they are in the faith. This self-examination is crucial for assessing one's spiritual state and dependency on Christ. It involves reflecting not only on one's sinfulness but also on the grace available through Jesus. The act of self-examination should lead to an acknowledgment of one's need for Christ, reminding believers that their assurance and acceptance come not from their feelings, but from God's promises and grace.