If you really want to understand Christianity (and I see that you do) you have to think of it the way you think of GOLF.

Does every golfer get a hole in one? Nope. In fact, no one has ever played a perfect game of golf (which would be 18 holes in one). Yet, people keep golfing because there is a way to get better by following the best possible ways to play the game. Christianity is exactly like that.