Salvation

So I've been doing some thinking lately about the nature of salvation, i.e. one time thing, process?? I came across something from Brian McLaren where he talks about the American church idea of the altar call (something I've always had issues with). He mentioned something about birth. That's when it hit me....John 3:3 talks about the new birth. Birth is a process....a gestation period if you will. I think alot of what we (the church) have tried to do in the past was to conceive and birth a new life in someone all at once at the end of a church service. Is it possible that this is why there are so many who fall away so fast? Pre-mature birth? Or, as a friend of mine likes to say, "we're in the business of sowing seeds, not trying to plant fully mature trees". Anyway.....