You must have confidence, not trust.

The opposite of confidence is doubt, and if someone sees doubt in your eyes, you will never build a mutual horizontal relationship.

Banks have relationships based on trust; they measure out exactly how much you can pay back. The association is transactional: doubt springs from analyzing the situation and finding risk.

Your job in a friendship is to believe in the other person; their job is to reciprocate with their best effort. You do not bully them with guilt; you allow them to find their best effort and develop pride in themself because you did not undermine them. Instead, your confidence provided them an opportunity to achieve.