I believe that my answer may be a little different from most and my offend some and hopefully edify others. Not meant to offend though.
All throughout the word of God the Lord Jesus is shown through allegories, similtudes, parables and types and shadows as the Husband and Head of his bride, the church. The second Adam that is a King and will not commit the sin of harkening unto the voice of his wife. he has all say and not the church. That is why he sent back his Spirit, the Holy Ghost to lead and guide her.
These same types and shadows can be seen in revelation. Paul wrote of them in Ephesians making the marriage very clear.
I really couldn't care less about secular marriages. Sadly however many mock that which is sacred in Christianity pertaining to the covenant of marriage with the Lord as it is written he that is joined unto the Lord is one spirit. Not non-believers alone but Christians as well.
Most straight cisgender men cannot get beyond their ego to say they are the betrothed virgin (in Christ) and bride of Jesus awaiting his return, deliverance, rescue and rapture. But in a spiritual sense that is what both male and female Christians are. His betrothed and one day bride adorned in his righteousness, or white linen. Personally I am his berothed and therefore that is why I do believe in a male and female marriage. That is also why I feel I may know how women feel to a certain extent.
Here in Illinois we have a civil union law that gives same sex couples full rights as heterosexual married couples. Makes me wonder why push for marriage. More so when a thousand march for the marriage right but only a hundred or so get married when it is passed.
I don't expect everyone to agree with me but if a couple can get full rights with a civil union why not just leave Jesus out of it?
After all, when you look at all of the men of God that were types and shadows of Jesus none were gay.
Adam, Noah, Noah's sons, Abraham, Isaac, Jacob, David, Samson, Joshua, Jeremiah, Ezekiel, Paul, Peter, Aquila and Priscilla, and countless others who were men and women of God were all straight.
Sadly many haggle over what it takes to be damned in the days of Noah and the days of Lot. Few stop to think that when each of these men the Lord referred to were saved they were examples of straight marriages.
I may enrage some but that's just what I believe to answer the original question. I don't want to offend any but by the same token don't want to deny the Lord or the word of God. It's not in my place to judge anyone or hate anyone. I would to God that all who call themselves Christians were saved. Even non-believers as well. But sadly many today stand behind pulpits and couldn't care less about the souls of those listening. Some just want to be seen and some just want to get rich. Few really care.
If any are offended I am sorry. But that is my answer to the original poster's question.
May God bless.