To mortify the old man means to put to death sinful behaviors and desires, actively pursuing holiness in the life of a believer (Colossians 3:5).
In Colossians 3:5, Paul exhorts believers to 'mortify therefore your members which are upon the earth.' This concept of mortification refers to actively putting to death those sinful behaviors that stem from our fallen nature. It implies a continuous struggle against the flesh and our old ways, as we, through the power of the Holy Spirit, seek to live in obedience to God. Mortifying the old man is an essential aspect of the Christian life, as it reflects a transformation that has taken place within us through the work of Christ, enabling us to pursue a life that honors God by reflecting the character of Christ.
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