The Bible has next to nothing to say on the subject of contraception.
At the beginning, of course, and again after the Flood, God commanded the human race to “be fruitful and increase in number and fill the earth.” (Genesis 9:1) So far, so straightforward – but several millions of years later we have more than filled the earth, so does He really intend us to carry on mindlessly increasing our numbers?
Refraining from sex isn’t the answer. Marriage is not to be despised (I Timothy 4:1-3), and those who are married should fulfil their ‘marital duty’ to their partner by having sex (I Corinthians 7:3-5)! And while we may no longer need to increase in number, we still need to produce enough children to keep the population stable!
So the question of contraception must be tackled. And the only other Bible passage that seems to be at all relevant is the story of Onan (Genesis 38:1-11)…
There are several aspects to this story that seem very strange to modern Europeans. The patriarchs of Israel inhabited a very different culture, and had different values. It was considered of paramount importance for a man to have at least one son to carry on his family line. So if he died without fathering a son, the ‘solution’ was for his widow to have sex with his brother, in the hope that she would have a son to inherit the dead man’s name and estate. This was called ‘levirate marriage’; and generations later the custom was written into Israel’s law (Deuteronomy 25:5-10). It wasn’t compulsory; but a brother who refused to ‘do his duty’ would be publicly shamed.
Why might the surviving brother refuse? Because of the inheritance rules that pertained at the time. A dead man’s estate would be divided between all his sons, but they didn’t get equal shares. The eldest son would receive a ‘double portion’ – twice as much as any of his brothers. Any child born of a levirate marriage would inherit the share of his mother’s dead husband; but if there was no child, that share would get added to the inheritance of the surviving brother(s).
Now we can begin to understand Onan’s dilemma. As the second of three brothers, he could expect to inherit one quarter of his father’s property (his elder brother would get half and his younger brother the other quarter). But when Er died childless, Onan became the eldest and stood to inherit two-thirds! If he did what was expected of him, his financial ‘loss’ would be considerable.
He could have simply refused – but instead he went ahead and had sex (repeatedly) with Tamar, while taking steps to ensure that she would never conceive by practising a form of contraception that we now call ‘coitus interruptus’ or ‘the withdrawal method’. “What he did was wicked in the LORD’s sight; so the LORD put him to death also.” (Genesis 38:10)
What are we to make of this? Is the use of contraception a terrible sin, that God considers punishable by death? I would say not, because if the use of contraception is so evil in itself, why is there no law against it elsewhere in the Old Testament? And in this specific situation there are several other factors to bear in mind:
1) There was more at stake than just family pride. It was Onan’s duty to father the next generation of God’s people. A whole tribe of descendants was depending on him!
2) He could have been honest and refused to do his duty – but instead he made a pretence of doing it, which is hypocrisy.
3) Onan was abusing Tamar. We know from the rest of the story that she was as keen as she could be to become a mother. But by having sex with her while depriving her of the opportunity to conceive, Onan was using her for his sexual gratification.
4) We shouldn’t overlook his other probable motivation, which was greed. He was, effectively, robbing his dead brother of his rightful inheritance – which in the eyes of society at the time was an extremely serious offence.
No decision to have sex, or to use contraception, takes place in a vacuum. Onan was doing something wicked; but that would probably not have been the case under different circumstances. There is always a context to the choices that we make; which is why most churches leave the issue of contraception to individual conscience.