Many of the main characters in the Bible had huge failings.
Moses – God told Moses he would be the rescuer of Israel. Moses kills and an Egyptian and spends the next 40 years in the desert watching sheep. Moses became a great leader after those forty years.
Samson – He was strong and foolish. Most of his failures were with his relationship with women. His last feat of strength brought a great victory over Israel’s enemy.
David – He committed adultery and murder. When David was confronted of his sins, he cried out to God for forgiveness and was called ‘a man after God’s won heart’.
Peter – He sank trying to walk on water, sliced a guys ear with a sword, and his worse failure: Peter denied that he knew Jesus three times. Peter knew forgiveness from failure and lived bold for Jesus doing miracles, telling others of Jesus. Tradition holds that Peter was martyred, killed for his faithful actions.
Paul – He killed Christians until he became a Christian! Paul thought he was doing something worthy for God and discovered that he trying to destroy what God was building. After Paul encountered Jesus, he became Christianity’s main spokesman at that time.
Not that I have already obtained all this, or have already arrived at my goal, but I press on to take hold of that for which Christ Jesus took hold of me. 13 Brothers and sisters, I do not consider myself yet to have taken hold of it. But one thing I do: Forgetting what is behind and straining toward what is ahead, 14 I press on toward the goal to win the prize for which God has called me heavenward in Christ Jesus.
If you let your failures be your best teacher, you will see what God will do in you.