This is a difficulty because no matter how good you are at following rules, eventually you are going to mess up. You will falter. There will be a violation, a discovery of the violation and eventually there will be punishment. You see, we are not perfect. At our best, we struggle with desires and wishes that will hurt ourselves and others. No matter how much we try, no matter how committed we are, we will violate one of the "do's" or one of the "don'ts".
I believe that Christianity is different, however. There are rules and expectations in the Christian faith, but they are less important than the central figure of the story. Jesus had an understanding of the imperfections of humans. He knew that we were going to sin. He knows even now when we sin. But the Christian faith (it is even hard to call it a religion at this point), is centered not on what we do or do not do. It is focused on what has already been accomplished by Jesus.
You see, there are consequences for our actions. Sins must be answered for. Jesus fixed it so that he would answer for our sins. His work provides forgiveness for you and I. This means that the importance of Christianity is found in our relationship with God through Christ, rather than an adherence to a legal code. When I am in relationship with God he knows my attitudes, my heart, my priorities.
I can know that I am in good standing with God not because of my faithful obedience, but because of what Jesus has done, and continues to do, for me.