Ideally, Christians are always ready to give an answer for their hope and faith to anyone who asks. In practice, however, we usually don't have a convincing answer until someone asks for it. That's when we first begin to reflect on our own views.
This explains the situation many of us find ourselves in today, concerning our views on marriage. We firmly believe that it is a life-long commitment between a man and a woman. But when challenged, we can't think of any persuasive arguments, and our view appears to be no more than a blind, unjust prejudice.
For those, who, like me, want to better understand their own views on this all-important subject, and be able to give a reason for it, I recommend this article by Maria Fedoryka. (Hat tip to Patrick Dunn.) Unlike many others who focus almost exclusive attention on the fruitfulness of marriage, her piece zooms in on the issue of gender: what it is and why it matters so much.
P.S. Maria gave two great talks for us a while back. You can find them here and here.