I'm torn on this one. On one hand, there have been studies done showing a central section of homosexual's brains are the same as a straight woman's, and a lesbian's is the same size as a man. There's other tests showing different hormone levels, etc. Also, I don't think many of the homosexuals want to choose the stigma and ostracizing that's prevelant today.
But then, many of the ones I know either came from either fatherless homes or didn't get along with their male role models. With that, they were effeminate to start with, and their situation just exacerbated it.
Should this, then, be treated by Christians as a mental illness?
I know the LCMS's stand on it. For the most part, I believe that traditional marriage should be between a man and a woman. However, if they want to leave their gov't. benefits to their survivor on death, I say so be it. Call it a civil union, because it can't be sanctioned by God, and not truly a marriage.