The question was put: "Current prophets are probably wrong about some point of doctrine or another. We know this because past LDS prophets have been wrong about the laws of God, and we have no reason to believe that current prophets are any less fallible. So why is disobeying a prophet such a big deal? Is it worse to say that President Monson is wrong about the sinfulness of same-sex relations than that President Young was wrong about the sinfulness of interracial relations? At least one prominent Mormon apologist has said that Young was wrong, but none have said that Monson is wrong. Why? What standard do Mormons use to determine whether it's permissible to contradict one of their prophets?"
To which I responded:
Some conservative Mormons answer this question with two main positions: (1) denial of either prophetic error altogether, or denial of the possibility that the current prophet could be in error; and (2) the fallback position that, in case we follow the errors of a living prophet, God will forgive us and only hold the leader responsible, but it is our duty nevertheless to follow the living prophet. I do not subscribe to any of the above views, and probably have not since I was about in elementary or middle school.
Above all else, (and subject to the limitations which I will describe) we have not only the right but the obligation to follow our own conscience, even if it contradicts the doctrinal pronouncements and behavioral edicts of the living prophet. But this right in and of itself does not give us a free moral pass to simply do whatever we please. We have an affirmative obligation to honestly seek truth and knowledge, to contemplate competing ideas, arguments, and information, and to make reasonable sacrifices for the betterment of ourselves and the world. So long as we are doing those things, and are striving to be good, then our own conscience trumps any purported doctrine or commandment. Were it not so, we could find ourselves subject to abuse, engaging in harmful behavior, or otherwise being misled in very dangerous ways. Brigham Young taught that members should think for themselves and not blindly follow.