The excerpts from Augustine, Calvin, and Luther were previously published on BaylyBlog, a joint venture of Tim Bayly and David Bayly, two brothers who are both PCA pastors in the Midwest.
Here is a link to the text of a sermon on birth control by David Bayly. He begins with a few implicit arguments from Scripture -- that children are a blessing from God, and as such are not to be limited; that we are still under the command to fill the earth and subdue it; that the Levitical laws concerning uncleanness after menstruation practically guarantee intercourse in the most fertile time of the month. Bayly says that these passages point toward God's will with regard to birth control.
He then deals at length with Genesis 38:1-11, and the account of Onan's wickedness and death. Specifically, the question is what is the sin for which God punishes Onan. Bayly writes:
Because we're not given an explicit answer in our passage, two theories have come to dominate thinking about this passage today: one a modern explanation and one the explanation of the Church universal for 1900 years up till the mid-20 th century. In recent years, many have suggested that the sin of Onan was his failure to provide offspring for his dead brother. This is not the classic view of this passage, but if you have spent your life within evangelical Protestant circles, it's likely that this is the only explanation you have ever heard for the wickedness Onan committed in the sight of the Lord.
The second explanation is the one which has dominated church history, yet it is almost unheard-of in Protestant circles today. By this explanation, what Onan did which was wicked in the sight of the Lord was his specific method of denying Tamar a child. This explanation says that it was Onan's practice of coitus interruptus, the only common and universally available form of birth control in ancient times, which lies at the root of his sin. By this view, God punishes Onan with death not for denying his brother offspring but for spilling his seed upon the ground.
Bayly points out that this is one of the rare occasions where God directly puts someone to death for his wickedness, which puts Onan in a league with Ananias and Sapphira and Nadab and Abihu. What follows is a methodical account of the flaws in the first explanation (and a third as well), leaving us with only the classical view of Onan's sin.
He brings his argument to this conclusion:
Is birth control permitted? I am increasingly persuaded by God's Word that it is not, that, as Calvin suggests, it is a form of abortion.
He acknowledges that one's situation may make this an especially hard teaching, but dismisses the importance of circumstances:
But may I say to you that our sensitivities cannot become our hermeneutic: we cannot let our personal situations and reasons for feeling a certain way about any passage be the decisive filter through which we view that passage. This is not faithfulness to the Word of God.
To date, the PCA, Bayly's denomination, has not issued a statement regarding contraception.