Paul spoke of the struggle between keeping the law and continuing to sin.  He struggled with it, even though he had been blinded by the light and was able to do miracles.  It was the same with the apostles.  They may have had strong spirits, but Jesus knew they were still flesh and blood men who would sometimes slip into sin.

So, what do we do?  Well, mainly, we ask for forgiveness after we sin and then strive to do better.  That really is all we can do.  We should draw on the experiences of the men and women of the Bible who saw great things - and, did great things! - yet, still sinned and needed forgiveness.

Don't be too hard on yourself is the lesson.  The world teaches us to carry guilt and "pay for your mistakes."  Jesus absolutely is not that way with you.  Accept that you sin, have sinner, and are going to sin, ask for forgiveness and keep praying for strength against the areas of your walk you know are weakest.