In a leader there is no acceptable substitute for character. Then you can help shape values and character in his life. If the person you are working with does not have character, you are wasting your time. It is paramount that there be integrity and trust between the mentor and the student at all times. When there is a mutual trust, much can be accomplished.
Values are so important because values affect performance.
A mentor is an educator in that he is teaching principles and skills. He is offering wisdom and advice. The mentor offers encouragement in every aspect of ministry. He is to be a positive force in the life of the student. He lends support and encouragement in the good times as well as the bad.