Children are a blessing. From their downy heads to their precious toes, they are miracles and gifts. I have three, and they are some of my greatest joys. But..... this doesn't mean that I want to have 11 of them. You can have too much of a good thing! It would be wrong of me to sacrifice my health, my ability to parent those I have, or my ability to feed and clothe those I have in order to have more, would it not? Would it not also be wrong of me to knowingly sacrifice a calling of vocation or service so that I could have 12 or 15 children when that is not my desire or what I believe is the right path for my life? I've often wondered- why is it that so many conservative Christians believe that birth control is wrong?
The bible doesn't specifically say so; the only argument I've heard there is the story of Onan and Tamar, found in Genesis 38:6-10. In this story, Onan was obligated to impregnate his brother's widow to fulfill the levirate marriage customs and give her a son to support her in her old age. Onan is intimate with Tamar, his sister-in-law, but he ejaculates on the ground instead of doing his familial duty, and God strikes him dead. In my study of this story, he was clearly punished for neglecting his duty, not for having sex without procreation. The idea seems a bit ludicrous, to be honest. Look at the family sizes in scripture. There are some notable exceptions, but 2-6 children is common. More than 12 is almost unheard of. Yes, some of that may be due to infant mortality rates, but not all I think. Moses' parents only had three. We have historic evidence that birth control has been practiced throughout recorded human history; a plant became extinct in the 2nd century because it was so valuable as a contraceptive.
In the creation story, God tells Adam and Eve to "be fruitful and multiply, to fill the earth and subdue it." My questions are these: 1. Does that mean that they must have as many children as possible, without any birth control being allowed to space things out, and 2. Is "fill the earth" still a primary command to us? In answer to number one, no. There is no mention of just how much multiplication is necessary. While the bible likens children to arrows in the hand of an archer, and blesses the man with a full quiver, there is no prescriptive designation for exactly what constitutes a full quiver. In answer to my second question: while the earth is by no means "full," we have a sizable enough population that our extinction is not exactly imminent. When God spoke to Adam and Eve, they were the only humans, and were commanded to basically start a civilization. Mission accomplished, I think. :) It is logical to assume that the injunction for humans to rule our planet as wise stewards is still very much in effect; it is not logical to assume that the same requirements for procreation and multiplication of humans are needed now that we have a population in excess of 1 Billion as were needed when a single sterile couple could doom the human race. Nowhere in scripture is birth control prohibited. In fact, in the prophecy of the end times in Matthew 24, we are told that it those times of great upheaval and distress it is a bad thing to be pregnant or nursing. There are times when even the blessing of children is a curse.
Part of the issue, I think, is something I've heard referred to as the "idolatry of the family." Basically that is a disproportionate emphasis on family relationships and responsibilities as Christian duty- think "women's chief goal is to be a godly wife and mother." I'm not saying that having a family is a bad thing, (it's not) or that once you have a family you should neglect them. Paul says in 1 Corinthians 7 that while being married is not wrong, serving God in undistracted singleness is a very good thing. Our primary purpose, men and women, is not to procreate but to live as followers of Christ. In my mind, the great commission is as important as birthing and raising children. Having a family is a good thing, but it would be a mistake to link that life purpose, one of several possible life paths, to holiness and Christlikeness. If being married is not the end-all for believers, neither is having children. And if being single can be a positive thing for the Kingdom of God, so too can childlessness. The same arguments that make a case for celibacy as a lack of distraction in Christian service could be made for childlessness. Of course, sometimes being married or having children is the best option and the best way we can serve God and fulfill the longings and callings God's given us. But that is a personal choice, between us and our Lord, and not a moral decision.