The Old Man:
The Old Man obeys the lust of the flesh, he is a slave of sin (John 8:34), whatever the lusts in his flesh tells him to do, he will do. When he sins he does it because he wants to, just like a pig who wallows in mud. In the Old Testament, the old man is pictured as the Israelites who were slaves in Egypt.
The Lusts of the Flesh:
The lust in our flesh will always be there till the last day of our life. We will always need to battle the lust in our flesh. We feed the flesh by giving into its desires.
The Old Man was like a unfaithful servant who always let the lust of the flesh into my heart and caused me to sin.
The New Man:
When I repent of my sins and receive God’s forgiveness (Acts 3:19, I John 1:9), I’m born of His Spirit and have a new man that is created in the likeness of God in righteousness and holiness (Eph. 4:24). My old man is crucified with Christ (Rom. 6:6). Though my sins were as scarlet I’m made white as snow (Isaiah 1:18). I’m like a cat who when I fall in the mud I get back out, unlike the pig I don’t want to remain in sin.
The New Man is a faithful servant who does not want to sin but may still fall into sin and give into the lust of the flesh, if the new man is weak.
The New Man must be strengthen through God’s Word (I Peter 2:2; Heb. 5:12-14), God’s Spirit (Eph. 3:16), and Grace (I Peter 5:5; Heb. 13:9, Rom. 6:14). If I fall into sin I shouldn’t justify myself but rather see if I’ve been faithful to be fed in God’s word, sought the power of God’s Holy Spirit and if I’ve been humble so as to receive His grace.
We don’t automatically overcome sin, we need to be obedient to put to death the flesh with the help of God’s Holy Spirit (Rom. 8:13). May the Lord help each of us.