Joseph Smith Jr. said this quote

Happiness is the object and design of our existence; and will be the end thereof, if we pursue the path that leads to it; and this path is virtue, uprightness, faithfulness, holiness, and keeping all the commandments of God.

~ Joseph Smith Jr.

Nothing is so much calculated to lead people to forsake sin as to take them by the hand and to watch over them in tenderness. When persons manifest the least kindness and love to me, O what pow'r it has over my mind.

~ Joseph Smith Jr.

God himself, finding he was in the midst of spirits and glory, because he was more intelligent, saw proper to institute laws whereby the rest could have a privilege to advance like himself. The relationship we have with God places us in a situation to advance in knowledge. He has power to institute laws to instruct the weaker intelligences, that they may be exalted with Himself, so that they might have one glory upon another, and all that knowledge, power, glory, and intelligence, which is requisite in order to save them in the world of spirits. (King Follett Discourse)

~ Joseph Smith Jr.

The exaltation and happiness of any community, goes hand in hand with the knowledge possessed by the people, when applied to laudable ends; whereupon we can exclaim like the wise man; righteousness exalteth a nation; for righteousness embraces knowledge and knowledge is power.

~ Joseph Smith Jr.