What country are you living in?!? So in the past few years we have had twenty-something states pass constitutional amendments AGAINST gay marriage by OVERWHELMING margins. That doesn't say the homosexual behavior is normal.
Homosexuality is no different than any other sin - alcoholism, addicted to porn, bestiality, etc. It has NEVER been proved to be genetic. It kills the person 20 years early. One might as well advocate for smoking - it only takes a few years off of one's life.
The liberal media has doe a great job of promoting homosexuality as "normal." That doesn't make it normal. Bestiality is now being promoted - who are we to judge?
You should be aware that the statistics about smoking and homosexuality are rather similar. Research done prior to the advent of protease inhibitors (the antivirals that have extended the lives of people with HIV), showed that homosexual men live between 8 and 20 years less than normal on average. (The uncertainty was mainly due to an uncertainty as to what percent of the male population is homosexual.) But cigarettes reduce the lives of smokers by an average of fourteen years (see http://www.cdc.gov/tobacco/research_data/economics/mm5425_highlights.htm.)
You are correct that homosexuality has not been proven to be genetic. However, there is evidence that genetics plays a role. (Up to 50%, according to research involving identical twins.) But the truth is that no one knows the cause of homosexuality. Most likely environment and genetics both play a role. None of the usual theories seem to work very well at predicting sexuality. For example, some say that a distant father, or sexual abuse at the hands of a male, etc, cause homosexuality -- but the rub with such theories is that there are plenty of heterosexual men with similar unfortunate experiences.