However, I'm going to show him your post tonight and hopefully he will agree that it's worth a try.
I have learned this painfully with my child growing up in the LDS community. I let things slide often not thinking it is worth a battle.
Funniest life is long and eternal and all righteous people will choose the right at the end.
Simply tell him that you line like your relationship is stagnating, and you'd like to talk about where it is going.