"When God created the world, He established a fundamental distinction within the human race, reflected in the human body: "male and female created He them." In the creation order upon which God pronounced His benediction, there were but two sexes; the human body was deliberately shaped male (zakar) and female (neqevah) the Hebrew words referring specifically to biological, sexual distinction. This natural difference defines and underlies the polarities of man and woman: such a distinction is not an arbitrary accident of evolution (as though survival of the fittest preserved only species able to procreate by couples), nor a mere cultural convention having the force of long-standing tradition. The distinction enunciated in Genesis is more than incidental historical detail. It is a declaration of the proper creation order, cited with authoritative approval and moral significance by Christ. It was God's ordained design for sexual relations to be in the form of male-female union, man and wife becoming "one flesh," and God created the distinction between the sexes to that end. This creation of sexual differentiation by God from the beginning established heterosexuality as the normative direction for the sexual impulse and act" (G.Bahnsen) http://www.ccel.us/homosexuality.toc.html