|The Word of Wisdom (D&C 89) doesn't ask much of us -- only to avoid consuming harmful chemicals. Better physical health is among the benefits or blessings this revelation promises to the obedient.
Although the obvious benefit is better physical health, I believe that the most important benefit of this revelation is spiritual. It promises "wisdom and great treasures of knowledge, even hidden treasures" to the obedient. Perhaps the most important knowledge obtained through this promise is a testimony of God and of the restoration of His church and priesthood. Failure to obey the Word of Wisdom is probably the most common attribute among those who do not have a meaningful testimony. It is probably the most common attribute among those who say they do not receive answers to their prayers. Interesting, isn't it?
Elder Boyd K. Packer said, "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." (Let Not Your Heart Be Troubled, p 211)
This revelation was initially given to us "not by commandment." But, remember that God has given us our free agency -- he wants us to make good choices, and he expects us to make those choices on our own. In D&C 58:26 he says "...it is not meet that I should command in all things; for he that is compelled in all things, the same is a slothful and not a wise servant; wherefore he receiveth no reward."
Perhaps because the Word of Wisdom is such a simple and easily followed revelation, many members haven't taken it seriously. Because of the failure of many early church members to follow the Word of Wisdom, the spirituality of the church was deeply affected. The Lord therefore saw the need to make the Word of Wisdom a commandment. It is truly sad that a revelation which is so easy to follow and which was given with such great promises is treated so trivially by church members, past and present.
Some members of my own family have had weak testimonies. Their weak testimonies are a natural consequence of the choices they have made, including their disregard of the Word of Wisdom. Weak testimonies and poor choice-making have caused some very serious problems in our family including criminal charges and even prison time and forfeiture of civil rights. The effects of poor choices can be very lasting.
Notice that I said that their testimonies are weak -- not that they have no testimony. They do have a testimony. They know what is right and good. They know how they should make their decisions. But, they have made some poor decisions, the consequences of which they can never undo. They will affect the rest of their lives. They have forever lost the opportunity to experience some of the most precious blessings life has to offer to the faithful. They will always regret it.
However, we do believe in repentance. When people choose to change the way they make their choices, they will no longer miss out on future blessings of obedience. I urge all to begin with sincere and prayerful obedience to the Word of Wisdom. To truly be sincere, one must think very carefully about what God intended for us to avoid -- anything which is addictive, which is physically harmful and anything which adversely affects our spiritual health. If coffee is bad because of the caffeine, then surely any beverage with as much (or more) caffeine as a cup of coffee is just as harmful.
Remember that obedience is a choice. When one does what is right, that person gets the credit -- not me, God, nor anyone else. If one does what one already knows one should do, that person is the winner -- not the loser in a battle against those who encourage wise choices.
With obedience to the Word of Wisdom much of the bitterness in the lives people everywhere will disappear, their testimonies will grow, they will feel better about themselves and the church, and good things will happen for them.
No one will never regret following God's commandments and living the standards of the church. We will always regret the choices we make which are contrary to the counsel of the Lord and His prophets. We don't intend to live with regret and disappointment in the future -- but that is the path we choose when we disobey the guidance of the Lord and his prophets.
The choice is yours.