Boyd K. Packer taught,

Our physical body is the instrument of our spirit. In that marvelous revelation, the Word of Wisdom, we are told how to keep our bodies free from impurities which might dull, even destroy, those delicate physical senses which have to do with spiritual communication.

The Word of Wisdom is a key to individual revelation. It was given as “a principle with promise, adapted to the capacity of the weak and the weakest of all saints.” ( D&C 89:3.)

“Revelation in a Changing World”
October 1989 General Conference