Timothy S. Lane and Paul David Tripp, How People Change (Greensboro, NC: New Growth, 2006), 175:

What If You Fail?

Never a day goes by when we do not fail to do what Christ has enabled us to do. Despite all of the gifts flowing from our union with Christ, sin still remains in us. That’s the reason you need to know that Jesus has broken the power of sin–because its presence still remains! We should not be shocked that the war still rages inside us. We have been changed, we have been empowered, but we have not yet been perfected.

What do you do when you sin and fail? Do you excuse and rationalize? Do you wallow in self-defeating guilt and regret? The Cross calls you away from both responses. It gives you the freedom to admit your sin and repent. It is impossible for your sin to shock the One who died because of it. The Cross also gives you the freedom to seek and receive forgiveness each time you fall. We do not have to carry the sins Christ took on himself. He paid the price we could not pay so that we would never have to pay it again.

When you fail, keep Jesus and his work in view. Run to your Lord, not away from him. Receive his forgiveness, get back up, and follow him once more, knowing that each time you fail, you can experience your identity as one for whom Christ died. Each failure reminds us of why he had to die; each confession reminds us of the forgiveness that only the Cross could provide.