Along the lines of my last post . . . I also, in a sense, don't think that anybody really changes much. It is hard to describe how I see this because I'm not saying that people don't change. We do . . . but it seems to me that it is more like . . . that it just happens. I don't see that WE do anything to change ourselves, ie., for the better. Mostly, my thought is . . . that we remain pretty much the same person we always were, but our circumstances change. Often, when we assume or assert that we are "better" people than we use to be (ie., because of being more "Godly", more "regenerate")) . . . I'm not so sure that we actually are. I think it is more like that God PRESERVES us more is all--protects us more . . . and keeps us out of situations where we would fall on our face just as swiftly as we did when we were "foolish". If the right conditions are there, we would be just as dishonest, lustful, cowardly . . . or whatever else makes up our particular sin weak-spots--as we ever might have been . . . when we were silly, immature teenagers or self-centered, know-it-all, 20-something yr. olds. . . .
If we do actually change for the better, I suspect it is only in very, very tiny ways--not much of substance, though it may appear like a radical change; but only because God is preserving us from sullying ourselves by keeping certain people and/or situations or temptations far enough away that we don't instantly fall into them. . . . It is easy to delude ourselves that "my, aren't I doing well these days, keeping out of sin!" When it is but God keeping it away from us. . . .
At the same time, it does seem true that we do not seek out sin in the way we once did, and this is a change, it would seem. Then again, I'm not sure that any such difference in us is really very substantive. Again, I would say that it is just God putting a hedge around our generally fallen proclivities so that the dastardly drive to sin that we have within is not constantly percolating as it once might have been. It is still there, dormant, but the Lord has "sealed" it in effect. It doesn't take long, if one DOES slip up (ie., God pulls back the hedge a bit) for a rare, stumbling sin, if repeated, to soon and once again become habitual and a real problem.
All I can say is that we are far more dependent on God--and ought be desperately grateful to Him, for all that He preserves us from . . . which we would otherwise fall into with gusto, according to our fallen natures. Until the End, when we shall at last be safe, I tend to believe this is how it is for the whole of this mortal, corrupt life, in this world, at this time. . . .