"In order to have joy, you need to understand that, as a child of your Heavenly Father, you inherited divine traits and spiritual needs - and just like a fish needs water, you need the gospel and the companionship of the Holy Ghost to be truly, deeply happy. Because you are the offspring of God, [whether you believe it or not, you are], it is incompatible with your eternal nature to do wrong and feel right. It cannot be done. It is part of your spiritual DNA, as it were, that peace, joy, and happiness will be yours only to the degree you live the gospel."
Marcus B. Nash