The man sounds like a saint. If knowing the Lord was his underlying motivation and strength, he will receive his reward in heaven.
But, he did what he thought was right and didn't waver. Even his mother, my aunt, another staunch Baptist, tried to dissuade him from remaining married to her, that she was never capable of being a wife to him from the very outset and that he was deceived into the marriage, therefore it was not valid.
He stayed with her until he left this world. I doubt I could have done it, myself.