D&C 89

 We are told why the Lord provided us the "word of wisdom" - 

"Given for a principle with promise, adapted to the capacity of the weak and the weakest of all saints, who are or can be called saints.

4 Behold, verily, thus saith the Lord unto you: In consequence of evils and designs which do and will exist in the hearts of conspiring men in the last days, I have warned you, and forewarn you, by giving unto you this word of wisdom by revelation—"  (Doctrine and Covenants 89:3–4)

Is there a better reason to live this law?