I needed to add something onto this. Some have not the ability to pro-create. How can they aspire to the command to pro-create when they cannot pro-create? The pro-creation command to male and female is first and foremost derived from Gen. 1:26-27 and is primarily for married couples. However, what is significant about being created male and female in his image is that neither male nor female are created separately in his image but rather together in his image. For some, this does not make sense but this means that in being conformed to the image of God we are given one major assignment–we are to assume both masculinity and femininity.
Let me give an example from St Hildegard of Bingen a significant champion of Western dogmatic theology. When God addressed her, he could have used “mulier” but he did not. Mulier is the Latin for woman and viro is the Latin for man. God addressed her as “homos”–human being. This is significant. As God himself exceeds and transcends gender, being conformed to the image of God himself also means to exceed and transcend gender. The whole basis of sexual ethics to me seems to be found in the following passages–Gen. 1:26-27, 1 Cor. 7:4, Eph. 5:22-31, and 1 Cor. 11:11-12. These passages seem to emphasize quite well the theological anthropology of the relationship between man and woman and form the basis of human sexuality. All must then therefore be examined in light of these. If something falls short, one can guarantee it is a fruitless endeavor to conformity with the image of God.
Some have said to me that since God has denied some the ability to pro-create he cannot possibly mean that pro-creation is the divine goal of human sexuality. We must not forget that Gen. 1:26-27 stems from the pre-Fall error. Sin was what brought death into the world (Rom. 5:12-21). Thus, all physical ailments are effects of human sin that was brought into the world by Adam’s sin. Further, those who cannot satisfy it physically are granted to satisfy it spiritually in a way only God knows how.
Some find the completion of their masculinity and feminity in their marriage with their spouse, some find it by embracing who they are in relation to God for in God gender is transcended.