Let's consider a standard Catholic objection to "artificial" birth control:
During our second year at seminary, however, Kimberly discovered the lie that was at the root of our married life. In research for an ethics course, she found that, until 1930, Christian churches-without exception-condemned contraception in the strongest terms. The Protestant reformers, whom we revered, went so far as to call it "murder". Scott Hahn, "A Life in the Language of Love–Birth Control and Contraception".
That's a popular Catholic trope which gets cited time and again.
i) From the standpoint of Protestant epistemology, that's an illicit argument from authority. Traditional opposition to contraception doesn't make the tradition true. That's a circular appeal.
ii) Some denominations (e.g. Roman Catholicism, Eastern Orthodoxy) foster groupthink. You're supposed to believe whatever your religious superiors tell you. In that case, a consensus of opinion is just a synonym for groupthink.
There's an elementary distinction between, say, people who independently arrive at the same conclusion, and people who think alike because they relinquish their judgment to a second party. For instance, cults may have great internal unity, but that's groupthink; that's unity based on rubber-stamping whatever the cult leader says. And that's the nature of very authoritarian, topdown religious institutions.
iii) One of the virtues of Protestant theology is that we are free to revise traditional errors.
iv) Before the advent of modern science in reference to understanding the reproductive system, contraceptive technologies and pharmaceuticals, was there a meaningful distinction between contraception and abortion? Traditional opposition to contraception might well be justified at a time when "contraception" was really an attempt to induce abortion.
But it's anachronistic to apply that to the contemporary situation.The modern scientific ability to distinguish between conception, contraception, and abortion provides new information and creates new possibilities that did not exist before then. Absent relevant medical knowledge to distinguish between conception, contraception, and abortion, as well as lack of technology or pharmaceuticals which could be that discriminating, it made sense to support a blanket ban.
To take a comparison, if a farmer doesn't know how much pesticide will kill all the insects, he will play it safe by using more rather than less to buy himself a margin of error.
v) I'm simply responding to Catholic apologists on their own terms. There are people who think there's something impressive and disturbing about the fact that there's been a shift in Protestant theology regarding the permissibility of artificial contraception. I'm pointing out that the Catholic appeal to prior consensus ignores the basis of consensus. If the grounds for opposing something shift, then opposition may logically shift, inasmuch as the original basis for opposition is now defunct.
The mere fact that a belief is prevalent doesn't create any presumption that it's true. And even if it was justified at the time, that can be due to considerations which are now obsolete. If traditional opposition to contraception was based on the information and resources at the time, which has been rendered obsolete by subsequent developments, then the traditional position now operates on a faulty premise.