I have seen people who are right, come across as irritatingly proud or condescending, when all they think they are is right. They don't think they are perfect, and being human they react to people who become antagonistic toward them. Some of them have gotten in the habit of being pre-emptively antagonistic. But I think you would agree, when you know something for sure, it gives a certain air of confidence. It can be taken as pride or arrogance. True faith in God doesn't have to be understood to give one confidence, but when what one believes seems to them to be backed up by scripture, and by reason, and experience, in many different ways/ references/ logical sequences/ events and assessments, yeah, it can make them very confident.
But I guess I'm not telling you anything you don't already know.