Happiness is.
A significant and oft-quoted axiom in the Book of Mormon is "wickedness never was happiness." In context, the passage explains why sinners inherit the Kingdom of the Devil after they die and are resurrected, but the saying is more popularly applied to the present.
"The way of the Lord is the way of happiness. Wickedness never was happiness. ... Disobedience never was happiness. The way of happiness is following the way of the Lord. I believe this with all my heart. If there is any message that runs through all of the Book of Mormon, it is this great transcendent message, that when the people lived in righteousness they were happy and they were prospered. And when they fell into wickedness they were miserable, they were at war, they were in poverty, they were in trouble. ... As it was true then, so it is true now." (Gordon B. Hinckley, Church News, 06/01/96)
When I was at BYU, this premise proved quite the conundrum for me. Before I accepted that I was gay, this belief was a major motivation for my attempts to become straight. If homosexuality is wickedness, and wickedness can't be happiness, then I don't want to be homosexual! Instead I tried to follow church teachings to the best of my abilities. The result? A lot of sadness.
I learned from experience early on at BYU that the inverse of the axiom, that righteousness is happiness, is definitely not true.
Once I began to meet other gay people, I noticed that a lot them seemed happy. And then I met a guy I liked, and I started to feel happy. And I mean actually happy, not some sort of fleeting pleasure that I was confusing for happiness. I mean the hopeful, fulfilling, at-peace-with-oneself, deep love sort of joy that comes with healthy companionship. This was the beginning of the end of my belief in the old Book of Mormon wickedness-isn't-happiness adage. That was nearly seven years ago.
As a Mormon I was always trying to find correlation between my level of happiness and my behavior. If I was happy, then I must be doing something right, and if I wasn't, then I was doing something wrong. But as I look back on my life now, I can see that there were times when I was doing things very "wrong" and yet was still happy, and there were times when I was doing the "right" thing and was miserable. When I was first coming out of the closet, I attributed this to a mistaken view of right and wrong. If a gay relationship makes me happy, then it must not be wrong. While this may be true, it does not completely explain why happiness and moral behavior don't line up.
I have found that no matter how you define right and wrong, happiness and sadness just seem to come and go. Happiness is not a good moral barometer. This is not to say that behaviors don't have natural consequences. There are many paths in life that we can choose, and some of them are happier than others. But at the end of the day, if I were to rewrite Alma chapter 41 in the Book of Mormon, I would write it to say this:
Happiness just is. Sadness just is.