Many times we don’t serve God because we feel unclean before him or we feel our gifts and abilities aren’t as good as someone else’s. First of all, “if we confess our sins, he is faithful and just and will forgive us our sins and purify us from all unrighteousness.” (1 John 1:9)
As for not being gifted enough, GOD DOESN’T NEED OUR ABILITIES. HE WANTS OUR AVAILABILITY. Isaiah has had tremendous influence on generations after he repented and said to God, “Here am I. Send me!” (Isaiah 6:8)