Luke 22:62 And Peter went out, and wept bitterly.
Peter had denied the Lord three times now. Jesus had looked at him. He hates what he has done. He is broken hearted. He runs from the place to cry and repent. The wonderful thing is that he gets right with God. In just a few dozen days Jesus will allow Him to be the man greatly used on the day of Pentecost.
We might fail and sin. We will fall. The question is will we realize we have done wrong, be sorry for it, and get up to serve again. God gave Peter a whole new life and chance to serve. He is good to us. Just be quick to realize your sin and turn from it to the Lord.