1. Service. Serving others is a hallmark of happy people. Selfless service connects us to the powers of heaven. As one Book of Mormon prophet said, "When ye are in the service of your fellow beings ye are only in the service of your God" (Mosiah 2:17).
Who and what we serve are just as important as how we serve. The Savior said, "No man can serve two masters" (Matthew 6:24). A person loyal to conflicting causes is disloyal to both. Likewise, those who gorge on self-indulgence are too bloated for selfless service.