Ephesians 2:3. “Among whom also we all had our conversation in times past in the lusts of our flesh, fulfilling the desires of the flesh, and of the mind; and were by nature the children of wrath, even as others.”
The Bible cuts us no slack just because we are believers. The truth is, all believers were, before coming to Christ, the “children of wrath.” We had our conversation (living out our lives, our behavior, companions, and words) among the children of wrath. Just like them, we coddled the lusts of our flesh and our minds. We partook of that which pleased our appetites, no matter how perverse and foolish those things may seem to us once we have become children of God. Our minds were full of self and sin.
We still are subject to the appetites and lusts of the flesh. That is why, later in this letter, Paul warns us to put on the whole armor of God. It is why I Peter 5:8 reminds us to be constantly on guard against Satan, who is like a roaring lion, looking for prey to devour.
The thing that keeps us from reverting back to our old behaviors ought to be a recognition that the blood of Jesus Christ was shed in great agony and love to redeem us from our old nature. The sacrifice He made on the cross was no small thing. If we focus on that, on Calvary and the empty tomb, it should bring us back from living according to the lusts of the flesh and of the mind.
If it doesn’t, if we are not moved by the recognition of what Jesus did, then perhaps it is time to re-examine the truth of our salvation. I am not one to constantly beat the drum of “Are you SURE you are saved?” However, if our lives and behaviors look a lot more like the children of wrath than they do the children of God, then a serious look at our true relationship with Him is in order.