What does the Bible say about putting off the old man and putting on the new man?

Colossians 3:5-10 instructs believers to put to death their earthly nature, which includes sinful behaviors such as fornication, uncleanness, and anger. This act of mortifying the old man means to make those sinful tendencies powerless, essentially putting them aside. Instead, the believer is called to put on the new man, which is created in Christ and embodies virtues like mercy, kindness, humility, and love. This transformation is vital as it exemplifies a true believer's relationship with Christ.