I think that we are called upon to conform to His image at every moment in our lives. I also believe that it is extremely rare that anyone could ever hope to conform at every moment in their lives. Impossible? I don't know, but unlikely, at the very least.
Does this mean we should just give up and admit defeat? Of course not. Some people buy lottery tickets hoping to win the big prize every week. Most never win. But they keep trying. The idea of that big payout is the carrot on a stick that keeps them motivated.
Once one experiences the difference in their own life that living in Christ brings, the motivation is much more than a carrot on a stick. Still, we are human, and bound to fall short of his image. When we use this as a goal, our falling short of it, even on a daily basis, is still much better than the life we live if we stop trying completely. Unfortunately, too many churches dangle the risk of ET as enticement to act right, and that just doesn't fly with me.