For this post, I was tempted to create another A.R. category – “Children” – because their best interest should be the focus of this issue.
A couple of commenters to Justin’s post have expressed scepticism as to Trayce Hansen’s thesis – that it is better for a child to be raised by a mother and a father. Commenter Jeff Gale stated that this conclusion is only Dr. Hansen’s opinion. Actually, it is an opinion based on extensive studies.
I’m going to take the importance of a mother as read and center on the father.
An article in the February issue of Acta Paediatrica analyzed twenty four papers published over a twenty year period. From the Science Daily review of that article:

Active father figures have a key role to play in reducing behaviour problems in boys and psychological problems in young women, according to a review published in the February issue of Acta Paediatrica.
Swedish researchers also found that regular positive contact reduces criminal behaviour among children in low-income families and enhances cognitive skills like intelligence, reasoning and language development.
Children who lived with both a mother and father figure also had less behavioural problems than those who just lived with their mother.

Let’s be clear. We are not talking about a mother or a father who finds him or herself in an unexpected difficult situation and makes the best of it. We are also not talking about a responsible, loving individual or a responsible, loving couple, gay or straight, who adopt an older child. This is obviously preferable to indefinitely bouncing the child from foster home to foster home.
The problem is the deliberate creation of a circumstance under which a child is raised without a mother or a father. The largest group of children in this category is not those with gay parents but those with mothers who got pregnant without arranging for or seriously expecting the father to be a day to day presence in the child’s life. That such a circumstance – the planned omission of a mother or a father, for whatever reason – should be avoided for the sake of the child is more than just an opinion.