The way you worded that would suggest that it’s our responsibility to teach him when in fact the responsibility is on him to learn. He’s not too dumb to learn, he’s just too much of a bigoted asshole to learn.
". . . those who claim to know the Mind of God, who will tell you what God thinks and how He will judge and condemn others—those people are the greatest of all blasphemers." Aloysius Xingu Leng Pendergast