The question was put:
"17-year-old John went too far with his girlfriend one Saturday night. The next morning, he blesses the Sacrament. Is the blessing still valid? Is the congregation still able to renew their covenants?"
To which I responded:
We are all unprofitable servants. The most important part of the ordinance is the faith of the one who takes the Sacrament, not the worthiness of the ones who bless it. If ordinances are considered "invalid" because the one performing it is "unworthy," then all of us priesthood holders may have to reconsider our "line of authority". If we accept that a sacrament blessing is invalid because the 17-yr. old priest went too far with his girlfriend the night before, then, before we could confidently claim to hold the priesthood, we would have to investigate the private sexual habits of each person in our chain, including Joseph Smith, Jr. I can't imagine God intended that result, unless either the priesthood is meaningless or can be wielded by an unworthy servant. Besides, I question the premise that the young man is truly unworthy because he went too far with his girlfriend. We all yield to temptations sometimes. What counts is our desire to do good and serve God. Though this boy yielded to temptation, I do not consider the offense necessarily grievous enough to deem him unfit to perform a priesthood ordinance, provided that he is striving in his heart to do what is right.