The only marriage we really see in From Here to Eternity is a totally terrible one: the marriage between Dana and Karen Holmes. Dana is an adulterer, a bully, and a total creep, and their marriage is so loveless that they're both openly looking for other people.
The marriages that are actually good are only those that might have been, like a marriage between Karen and Warden or between Prewitt and Lorene. As it stands, the movie tends to investigate "the woe that is in marriage" rather than any potential happiness.
Questions About Marriage
Is Captain Holmes and Karen's marriage a rare bad exception, or is it a more common than we realize?
How do you think Prewitt and Lorene would've worked out as a married couple? What about Karen and Warden?
What's lacking in Captain Holmes and Karen's marriage? What destroyed it and what's the main thing wrong with Captain Holmes?
How do you think these marital conflicts would've worked out in the present day? Would it have been different?
Chew on This
You can view From Here to Eternity as an argument against using marriage as a pointless trap. Karen and Holmes remain married yet completely unfaithful to each other—their marriage is an utterly hollow shell.
On the other hand, you can view From Here to Eternity as an argument for marriage—just not terrible ones.