Genesis 29 and 30

Whenever you feel like you are not good enough for God to use, remember the story of Jacob that is told here. You know the story, he goes to Laban and works for Leah and Rachael, and yes Laban was very wrong to trick him. Then toward the end when Jacob wants to leave, Jacob starts breeding the good stock for himself and the weak stock for Laban. Not a very Christ like thing to do if you ask me. But God went on to do great things through Jacob. So never feel like God can't use you because of something in your past. When the devil reminds you of your past, tell him you are forgiven and remind him of his future.