What is the 'old Adam' in a believer?
In a believer, the 'old Adam' is the part that never quits working on us. It is the part that gets greedy, envious, and covetous, and it is the production center of those thoughts and sins, not merely the sins themselves. Believers never reach perfection in this life.
Les explains that the 'old Adam' is not simply the individual sins a believer commits but the source from which they come. He says old Adam is that part of us that gets greedy, envious, and covetous—the part that sees what a neighbor has and says, 'I have to have that.' Les notes that old Adam is never going to quit working on us, so we never get to a place of perfection; even early in the morning we can be guilty in our thought processes. In Paul's words, it is no more I that do it, but old Adam. Paul warns against living on that plain, because believers no longer live there. Les finds this replacement of 'sin' with 'old Adam' opens up the Scripture: the problem is the production center of those thoughts and sins, which is old Adam.