Marriage Between a Man and a Woman is Ordained of God

http://lds.org/ensign/2011/06/the-latter-day-saint-concept-of-marriage?lang=eng&query=marriage+ordained+God

When my husband and I got married, it was a very special day. We weren't just getting married for this life, but for eternity. We made covenants with the Lord that we would do the things that He has commanded us to do so that we can return to live in His presence. I think it's important to note that marriage is supposed to be between a man and a woman. This is the only way God's purposes can be fulfilled.