You can't be fully prepared by following God's word you've to experience it under circumstances that can lead you to be an example of who can share and lead the people that believe in God's word.
Mistakes can't determine you. What you do after that determines your future. God wants you to accept it and move on, don't be in that mistake for long time.
God tests your patience but he never delay things for you. There is a difference in it try to understand the process behind it then You will understand everything in a different approach.