What it all comes down to, though, is do you believe President Thomas S. Monson is a prophet of God?, because - as they say - when the prophet speaks, the debate is over.
I don't say this to open old wounds, or cause further contention on the thread. I say this with all the love and understanding that I can muster. I also say this coming from the same position as you. I just don't get the big deal when it comes to gay marriage. So what?
HOWEVER, President Monson (and President Hinckley before him) has felt that this is not a political issue, and it is a moral issue, and as such, it is something that the Church has the obligation to weigh in on.
(And, again, so what ... even if it is a "legal" issue, the Church would be right to have a say in it, the Catholic Church is against such things as well, but there's no kerfuffle when the Pope weighs in ... why is it always an issue when the "Mormons" make a big deal about it?)
What matters is that you and I and all of us have a testimony of President Monson. THAT. IS. IT. I may not agree with the position. I may not understand the "why" of it. I just have to know that President Monson is a prophet of God and that the prophet will never lead the people of God astray (in other words, pray ... pray until you get an answer, not just get the answer you "think" you should have).
Again, I don't say that last out of spite or meanness. It comes from having been in the same position. I had just got home from my mission in Brasil when the First Presidency announced a change in missionary policy that I did not agree with. They changed it so that a newly baptized convert was no longer able to be confirmed and recieve the Holy Ghost directly after baptism, but instead was confirmed in Sacrament Meeting on the first Sunday after their baptism.
For many of the people that I had baptized on my mission, that meant they would have had a whole WEEK between baptism and confirmation and a whole WEEK that they would have been without the constant companionship of the Holy Ghost and a whole WEEK that Satan could get in and work on them.
I didn't understand it then. I don't understand it now. I didn't agree with it then. I don't agree with it now. HOWEVER, I had and have a testimony of the divine calling of then-President Hinckley and I accepted that there was a reason that I did not know or understand that prompted the change in policy.
Whether you believe me or not, the issue of gay marriage amounts - in the end - to the same and this is coming from someone who believes the same as you ... that there is no reason why we need to worry ourselves about this. Just let those poor people be. So what if they can marry?
Yet, the prophet of God has spoken, and what it comes down to is do you believe in his divine calling or not? If so, then it is clear what needs to happen. If not, then a lot of prayer is in order.
I honestly believe that this is a "wheat and tares" kind of issue - a sifting of the Church, if you will - many people will get angry and leave the Church over this issue which, in the end, is the wrong thing to do. However, my stating that fact will not change it. Prayer ... long, hard, earnest prayer is the only thing that can help you or me or anyone understand and accept the Church's stance on this, whether we agree with it or not.
Pray. That is my advice. Pray for understanding. Pray for knowledge. Pray for wisdom. Pray until your knees hurt. Pray to your Father in Heaven for help and understanding and guidance ... and then wait. Wait not for the answer you "think" you should get but wait until you get His answer.
Try to come to Him with an open mind and a clear heart, because if you go into this prayer antagonistically or with a preconcieved notion of what the outcome is going to be, there is no point. You need to come to this particular prayer as humble and meek as possible and then ask.
Ask if President Monson is a prophet. Ask if this is really God's will. Ask if this is something that the Church should be involved in. Then wait and listen for the answer from your heart ... and not your head. If the answer to any and all of these sincere questions is "yes," then in spite of anything you or I or anyone else may believe "logically," your course is clear.
That is my advice to you, and it is given with all the love, caring, understanding and compassion that I have because I have been in the same boat as you. This was how I found peace with it, and I hope and pray you can too.