I suggest you read the book and/or watch the movie I have suggested.   You might also check out "The case for Christianity" by CS Lewis.   At one point, CS Lewis was an atheist.   There are many atheists that have converted.   I agree that just because you believe, not all of your faults magically disappear.   Some things should change as you go through your walk.   A fun book in that regard is "Pilgrim's progress".   The original versions are all in Old English, but has been updated to be in modern english.  You might even be able to read it online.