The person in my life I consider to have the highest credibility is my local church pastor. I believe he is one of the most credible and trusted people in my life, because has several degrees relating to ministry and has been chosen by God to be a pastor. Since he was called to be a pastor, I think that gives him more credibility to be trusted because God specifically wanted him to be in that field. Our pastor also embodies trust in the way he supports our church.
A person with a strong character is a good reason to find them credible.