As followers of Christ, we are to take God at his Word and accept as true what he says we are. This means our “old man” represents a man who still seeks to please God in the flesh. Such a man hates sin, he doesn’t want to offend God, and yet his conscience continually brings him under guilt. So he pledges to overcome his sin problem: “I’m going to change! I’ll start today to fight my besetting sin, no matter what the cost. I want God to see how hard I am trying.”
Such a man brings to the Lord much sweat and many tears. He prays and fasts to prove to God that he has a good heart. He’s able to resist sin for days at a time, and so he tells himself, “If I can go for two days, then why not four, why not a week?” By the end of the month he feels good about himself, convinced he’s working himself free. But then his old sin surfaces, and down he goes, deep into despair. And that starts the cycle all over again. Such a man is on a treadmill that will never end, one he can’t get off.
May it never be! His man-in-flesh was crucified along with Christ, killed in the eyes of God. Indeed, Paul tells us that the old man was pronounced dead at the cross. Jesus took that old man into the grave with him, where he was left for dead and forgotten. Just as the prodigal’s father ignored the “old man” in his son, the Lord says of our old man, “I won’t recognize or deal with such a one. There is only one man I recognize now, one with whom I’ll deal. That is my Son, Jesus, and all who are in him by faith.”
The new man is the one who has given up all hope of pleasing God by any effort of the flesh. He has died to the old ways of the flesh. And by faith he has come to know there is only one way to please God, one way to delight him: Christ must become all. He knows that there is but One whom the Father recognizes: Christ and all who are in him.
This new man lives by faith alone: “The just shall live by faith.” He believes God’s Word so completely he leans on nothing else. He has found his source of everything in Christ, who is all sufficient. And he believes what God says of him: “Your old man is dead, and your life is hid with Christ in God.” He may not feel it, or comprehend it fully, but he won’t argue with his loving Father’s Word. He accepts it on faith, believing the Lord is faithful to his Word.