I think this is very very bad advice. You don't fix one mistake by making another one.

OP said that he dearly loves his wife. I think that's marvelous and he should treasure that. Divorce would indeed be selfish behavior, as you recognize. And that's not where you find happiness and a fulfilling life.

(Aside: your attempt to make the suggestion colorful by adding that the woman should be religious is quite weird. For many religious people, selfishness and divorce are not things that make a partner attractive.)

Why does she have to be religious?

She does not have to, I am merely painting a possible path in a colorful way.

sry, but the picture you're painting might be rational but I don't agree with it. Just because the divorce statistics might be bad doesn't mean you should breakup, just because he is unhappy now doesn't mean he will be unhappy in the future, same goes for the marriage, just because it's bad now doesn't mean it will be bad forever. Just because I want something doesn't mean I should go for it without looking left and right. You also lose something if you decide to change things. He could just adopt or maybe he would just like kids around him, so he could work in a soccer club, kindergarten or something else part time.

I merely emphasize the choice in his life, reminding that not all is lost.

Just because he does not divorce now does not mean that the partnership will hold.

Just because he breaks up and has kids with someone else does not mean that he will be happy.

Either way there is risk, and there is choice.

Choose wisely, Luke.