The struggle many people have with Mormons (LDS) is that they are genuinely ideologically captured. They have limited ability to individuate themselves as a person apart from their religious dogma.

Confronting the soundness of their religious teachings is, for them, an attack upon themselves personally. 

Given the fact their faith in the Book of Mormon is so profoundly rooted in the catharsis of emotional conviction, it is almost impossible to have a nuanced conversation about anything they accept as 'gospel' truth.

Sad, really. I'm not even bothered by the fictitious origins of their book. After all, the Iliad, Odyssey, and the Aeneid weren't historical facts either. For that matter, much of the Hebrew Bible (Old Testament) is allegorical and literary moral fiction. So what?

What I won't yield on is the ubiquitous acceptance and erosion of the soundness of their marital practices. (and no, i'm not talking about polygyny)

What might otherwise have been a genuinely sacred institution of marriage, emulating a covenant, has been reduced to a check box task on their way to eternal bliss of some kind.

They've completely overlooked the underlying necessity for a physical, emotional, and spiritual unity between the man and woman married together.

The divorce rate is outrageous, and although they do have a formal recognition of dissolution and release from covenant bond, it is rarely exercises in the face of obvious marital abandonment.

For me, that's a civilizational threat. I've been unwavering throughout my entire life that marriage between men and women is the only viable way to bring equality of the sexes, and indispensable to the continuity of civilization and survival of our species.

They've promoted their "temple marriage" in a way that reminds me of the phrase "having form of godliness but denying the power thereof".

The marriage has form, but the power is in the relationship between the spouses, not the 'authority' of the priesthood performing the ceremony.

I will keep trying.