Is it figuring out really complex theological dogma? Is it being rich in wealth? Is it getting any girl or guy you want? Is it winning an argument?
No. Truth is peace that comes from doing the right thing, even if others don't approve. I know too many folks who struggle in their lives for acceptance by others, precisely because they cannot accept themselves. And if you can't accept yourself, you surely don't feel like God accepts you either.
Simplicity, even amid complexity, brings happiness. So a faithful marriage is better than any faithless fling, flirtation or pornographic titillation can ever be. Because you are accepted of your spouse, and your spouse accepts you. Betrayal in this arena brings some of the deepest pain a person will ever experience. Success brings comfort in the journey.
The higher the quality of life it seems is strangely correlated to the length of life. Looking out for your personal health is an act of love for your spouse, children and loved ones who continually deal with the aftermath of personal neglect even, or maybe especially, after one dies. It seems basic, consistent health choices improve the quality of ones life, whatever the god-given circumstances of the beginning of one's life.
Studies show Mormons spend more time studying the Bible, in prayer, teaching their children and sharing their faith with others, and engaging in service, than any other faith. Studies also show active LDS enjoy the highest sense of life satisfaction of all people. And the IRS has identified the Mormons as the faith most giving of material wealth in America, while they at the same time are the most highly educated of any denomination as well. In fact, surveys show the LDS faith is the only religion in the US where more education is a predictor of religious participation. In other words, the smarter you are, the more likely you are to be an active Mormon, but the less likely to be active in other religious traditions.
Mormon temple marriages have the lowest rates of divorce of any religion in America. Of course it is not the act of being married in the temple, since there are divorces among those people too. It is a commitment to the principles such a marriage is designed to incorporate which helps steer couples through the obstacles of life, and end up still in love.
Probably as a result of the above principles and the traditional interpretation of the LDS health code called the Word of Wisdom, Mormons live on average 8 years longer, with a higher quality and satisfaction, than the US average. This is the longest addition to life of any identifiable group in the US.
Anti-Mormons complain that LDS doctrine is so simple it allows every person their own spin on many doctrines. I don't think that is an accident. God did not ever say a belief in the Trinity as defined in 381 A.D., and not 325 A.D. or some other counsel, is essential to salvation. Being LDS is a simple, comfortable, happy faith. Those who claim otherwise are usually those who think that God doesn't care how they live their lives. To some extent, he doesn't. That is, you can live life as you please, he just doesn't bless those who stray defiantly away. Come back and find peace. There are tests which make it easy to tell who follows the True Jesus:
By this shall all men know ye are my disciples, if ye have love one to another. (John 13:35)There are lots of nice people in churches, but Jesus' Church (Matt 16:18) is an institution of love, bringing the fruits of peace, happiness and comfort in the journey. It does not attack other faiths, but invites those in error to come and see where Christ really is.
Peace is the gift He left for us.