You already know the answer to these questions, in fact, it's right there in the question itself:
It is merely the consequence of his cultural circumstance. Had he been raised in ANY other religious culture, particularly one as insular as the mormon church, he'd be on board. The pressure to conform to the mormon lifestyle and belief system within the church and the community at large is tremendous. Even if it isn't explicit, outright coercion, it really isn't a viable option to rebuke the church unless you're willing to be excommunicated, ostracized, or consider moving and starting over.
He's already said point blank that had he not been raised as a mormon and only exposed to the doctrine and belief system as a discerning adult, he wouldn't believe. Honestly, who would? Very few people who independently (as independently as any idea/belief/or thought can be) decide as an adolescent or a young adult that god and religion is simply unbelievable go on to become overtly and devoutly religious.
I actually find his position intellectually dishonest, and the mental gymnastics necessary to compartmentalize and justify contradictory ideas completely ridiculous. There's this swelling of people who attempt to reconcile laughably and woefully inaccurate religious texts/dogma with our ever growing scientific understanding of the natural world, and it's the whole "god of the gaps" thing over and over again.
How can people with a straight face and sincerity, arbitrarily decide what bits are just "metaphor", symbolism, "literature", and what parts are 100% literal and to be followed to the letter at al costs? You have to willingly dismiss blatant contradictions and indulge an absurd level of delusion. It's so transparent. it's hard for me to understand how "seemingly" rational people can say things like, "no, no, I KNOW it says blahblah, but it REALLY means this totally arbitrary, focus group approved, less offensive blahblah! How do I know what it really means? Well, I read this explanation on this blog, and I think it sounded really good and figured it could help me win internet arguments so I personally just decided that it's true".
For example....the church's attitudes/beliefs towards black people and how they got that way....we all agree that it's ridiculous. It's come under such scrutiny that it's been stricken—but not before it was blindly defended for years. It's only been swept under the rug because society at large's attitude has finally gotten so ridiculously far away from the church's stance that it doesn't make economic sense to stand by that one particular belief anymore. And, that's the crux of the thing. There's no real integrity or concrete truth to any of it. It's all negotiable, open to "interpretation" and subject to change based on whatever allows the church to gain a foothold in mainstream culture and to grow and profit.
Yet, is that not just one small example of the myriad fairytales? And, call me cynical, but I find it a little more than convenient that the church who makes conversion and growth its driving force would back pedal a clearly alienating and excluding bit of doctrine. It's self-serving, and for an economic enterprise, it does no good whatsoever to so clearly and directly dismiss such a large, untapped group of potential suckers, I mean congregants. Surprise! Just kidding darkies, all aboard! Quick let's make a LDS commercial with a black mormon!
The fact that OP is happy, while good and I'm in favor of people being happy, is pretty irrelevant. If it ain't broke, don't fix it, so hey, keep chugging away.
Religion is a complete, total, utter, and obvious sham. If any discerning adult would ask themselves one or two very, very simple questions, it becomes really difficult to look in the mirror and say, "I truly believe in this particular set of religious beliefs". Those questions are: What makes this religion any more "real" than the thousands that have come before and will come after? What if I had been born on an island in the Pacific or in Africa instead of in the US and had never been exposed to such and such religion? Pure chance that one individual or another fosters strong religious convictions.
And, to whomever said "atheism is a religion like any other". That is a fantastic little sound bite, and it is a nice little zinger that will really leave the base frothing, but it's so obviously false and hollow that I won't even respond save to say one quick thing:
Being an atheist doesn't define a person's entire being, life, and/or purpose. It's simply an idea held about the nature of life that doesn't shape and define every other aspect of that person's life. There's no unifying behaviors, tendencies, or "right way" to be an atheist. You can't be a "bad" atheist like you can be a "bad" Christian, because there's no dogma, or tenets. I don't sit around and filter all of my life experiences and current events through my "atheist filter". You can however choose to be a good person, and it doesn't have to be motivated by fear of punishment or being denied eternal paradise.The burden of proof doesn't and will never rest on the shoulders of atheists to "disprove" god, or even to definitively prove how life and the universe began. Throughout history, there has been many, many phenomena that we've not been able to explain at that moment that was ascribed by the faithful and devout to god's work. As we learn more, god literally shrinks.