I can tell you that in my case my recognition of the right of same-sex couples to marry grew directly from the arguments mustered against it, because ultimately I realized they were also mustered against my wife, against me, and against the one person all the pro-marriage protestors and pamphleteers have pledged themselves to protect: My child.
John Fugelsang draws a contemporary parallel to the story of the Passion and Resurrection in this commentary. Does its analogy hold up for you?
If text, tradition, and reason/experience are unreliable guides, where then shall we turn?
Stop all the clocks, cut off the telephone, Prevent the dog from barking with a juicy bone, Silence the pianos and with muffled drum Bring