For all the modern-day controversy that the topic of surrogate motherhood has generated, it is right in the Bible, in the book of Genesis. We see the first example in the story of Abraham, Sarah and Hagar, in Genesis 16. It comes back with a vengeance in the story of Jacob and his competing wives Leah and Rachel. Rachel, who appears to be barren, offers Jacob her handmaid Bilhah, "That I may ... have children by her" (v. 3). After Bilhah gives birth to a son, Rachel names him Dan, and declares, "God... hath given me a son" (v. 6).
The Bible also allows for surrogate fatherhood. The principle of Levirate marriage, described in Deuteronomy 25: 5-6, mandated that when a man died without issue, one of his brothers should take his wife (or wives) and raise up children in his brother's name. The principle seems to have been understood before it was codified in the Mosaic law, as we see in Genesis 38:8, where Judah orders his son Onan to give children to his deceased son Er. Onan's sin -- the one for which God notoriously smote him -- was his deliberate denial of posthumous children to Er by interrupting the act of procreation with Er's wife Tamar and "spilling his seed upon the ground" (Genesis 38:9). Denying a brother offspring and a name appears to have been considered a very serious offense in the eyes of God.
From a Latter-day Saint perspective, the evidence of a clear biblical mandate for surrogate parenting is very interesting, if only because of the broader vicarious principle within our theology. Latter-day Saints see "saving our dead" as one of God's core commandments to the Church. That is why as a routine aspect of our service to God, we are baptized, confirmed, endowed, married and sealed in the temple on behalf of our dead ancestors, performing vicariously (or as "surrogates") for them ordinances which they (being dead) can no longer perform for themselves. In Genesis and Deuteronomy, we see the vicarious principle extended not merely to the performance of ordinances on behalf of the dead, but to the provision of offspring to those who are otherwise unable to have offspring of their own.
I love the vicarious principle. It teaches, first of all, that we are all interconnected. We are all one. The Doctrine of the Atonement is, by the way, an example of the vicarious principle -- perhaps the supreme example. The One who was able to bear the burden of our sins, bore it for us, on our behalf. Many have called the Atonement a "mystery" because they could not understand how justice could ever be served by having one person suffer for the sins of another. But it is less of a mystery in the framework of the vicarious principle. Apparently one who is worthy may voluntarily suffer on behalf of another who has sinned. And Latter-day Saints, by referring to those who perform vicarious temple ordinance work as "saviors in Mount Zion," in essence acknowledge that our vicarious ordinance work and the Atonement of Christ operate under the same principle.
One reason Latter-day Saints often argue that same-sex marriages cannot possibly be considered valid by God is because same-sex couples cannot have biological children of their own. Establishing families and having children is seen as a core element of God's plan for all of us. One reason I am fascinated by the principle of vicarious/surrogate parenting as it appears in the Bible is that it so clearly teaches how, from a divine perspective, lineage need not be biological.
Biological procreation necessarily brings children into the world. The union of a sperm and an egg is the only way I know of to create human children. But biological procreation is not how families are created or lineages are established. The building of families and the establishment of lineages takes place through covenants lovingly and freely entered into and fostered and renewed through sacrificial love.
The vicarious principle teaches that we are all one flesh, and that by virtue of our oneness, we have obligations to each other. In the biblical principle of vicarious parenting I see God telling us that we have an obligation to help others establish families and lineages in their own name. Shouldn't gay and lesbian couples who are seeking to build families for themselves receive the loving support of their heterosexual brothers and sisters?
In doing so, do we not more fully affirm the humanity of all of us?