Intelligence and Opinion

My children are all quite intelligent to some degree.  Most of them are fairly successful in their main focus in life.  I have one son who is brilliant but he is a man of set opinion.  When he has satisfied himself about the truth of a proposition he is very unlikely to change his mind.  On some subjects like the reality of God I find this very reassuring.  Eternal truth should not be a matter of casual affiliation, but there are some things that he doesn't have the best information about.  He will become very upset if his premises on these things are questioned.  I am confident that on particular matters his information is unfounded or outdated.  I need to realize that argument will do no good.  I have seen him change his mind on some matters when presented with more current and accurate information.  I am not the person likely to convince him in certain matters.  At least our deepest and most important beliefs are congruent.