one character who is trustworthy and why in the crucible story

I would say Elizabeth Proctor. She is a woman who has great confidence in her own morality and in the ability of a person to maintain a sense of righteousness, both internal and external, even when this principle conflicts with strict Christian doctrine. Although she is regarded as a woman of unimpeachable honesty, it is this reputation that causes her husband to be condemned when she lies about his affair with Abigail, thinking it will save him.