Birthparents and agencies must enjoy the right to place children within their wishes - and those wishes may include the religious rights, a Constitutionally-protected first freedom. 

A child benefits from having a mother AND a father.  It does not follow that to insist upon placement in a home with a mother and father will force children to go homeless, but it does follow that a child will be denied the benefit of a mother AND a father if this opportunity is willfully prevented by the adoption placement.