Instead of turning to a commentary or a devotional, the best way to interpret the Bible is to use other Scripture. So the first tool I recommend when it comes to diving into a passage is the cross-reference tool. If you don’t have a Bible with a built-in cross reference, I recommend you get one.
Every single day we must wake up and allow Christ to kill the old man. The flesh must die. The old man must be killed, the desires that raise up within you that desire things of the old man must die. Let Christ kill the old man every time he rears his ugly head. The old man will look strangely familiar—he will look more like you and be more dear to you then anyone else you know. But if Christ is to grow the New Man within you that looks more like Jesus, then the old man must go. There is no use in keeping him around, he will only drag you down to hell. The old flesh must die.