Polygamy is back! From highly-rated reality TV shows to guest appearances on Oprah, polygamy has become almost fashionable. And while the very idea of polygamy seems to run directly against the foundational understanding of Christian marriage, I foresee a trend toward polygamist normalization among a most unlikely sector: Bible-believing Christians.

I've already heard mutterings about "Biblically" justified polygamy among certain Christian groups and I think evangelical Christians are going to have a difficult fight on their hands when it comes to decrying polygamy.

My guess is that the justification for polygamy will be that it cannot be deemed sinful on the basis of Scripture alone. The oft-heralded Protestant method for weighing the "Biblicality" of cultural trends is the belief in "sola Scriptura"--or, the Bible alone as the Christian's sole authority. To the dismay of many Bible-only Christians, their very belief in "sola Scriptura" will be used against them in the defense of polygamy.

To my mind, condoning polygamy is simply what happens when you take "sola Scriptura" to its logical end.

I mean, even Martin Luther--the great Protestant Reformer--"concluded that monogamy was no necessary part of the Christian revelation and that polygamy was a legitimate practice for a Christian." (Shea, By What Authority? p. 101)

Here are Luther's own words:

I confess I cannot forbid a person to marry several wives, for it does not contradict the Scripture. If a man wishes to marry more than one wife he should be asked whether he is satisfied in his conscience that he may do so in accordance with the word of God. --De Wette, II, 459 (quoted in By What Authority? p.101)

So, according to Martin Luther, the only test required of a Christian man desiring to marry more than one wife was....that the man had a clear conscience about it!

And yet, most Christians would resoundingly disagree. The ban on polygamy has always been a non-negotiable part of Christian thought and practice--even when Christianity was surrounded by dominantly polygamous cultures.

But I think Luther has a point and it's the same point that will be used by "sola Scriptura" Christians in defense of polygamy: it does not contradict Scripture.

As Mark Shea insightfully enumerates in his book, "By What Authority?: an Evangelical discovers Catholic Tradition", all the verses in Scripture that pertain to sin in marriage have to do with taking another person's spouse, abandoning the wife of one's youth, marrying outside the Faith, polygamy by a woman, divorcing a wife and thereby leaving her few options (in 1st century culture). But 'nowhere is a man forbidden to take more than one wife at a time' with the exception of overseers/bishops. (p.104)

So why have Christians historically and consistently rejected polygamy?

Because rejecting polygamy was the orthodox Christian teaching BEFORE "sola Scriptura" was embraced by Protestant reformers.

In other words, long before the Protestant split from Catholicism--and its subsequent subdivisions and never-ending sub-sub-divisions--the teaching of the apostles and the practice of early Christians definitively eschewed the practice of polygamy.

Before the canon of Scripture was canonized, this was the tradition of the early Church handed down orally and through the epistles by the apostles.

All of which to say, if "sola Scriptura" Christians are going to try and decry the issue polygamy, they might find themselves reluctantly relying on the ancient Christian understanding: Scripture held hand-in-hand with apostolic tradition.

Or, as Paul wrote in 2 Thessalonians 2:15, "So then, brethren, stand firm and hold to the traditions which you were taught by us, either by word of mouth or by letter." (emphasis mine)

If more Bible-only Christians start searching out the apostolic tradition, I'm thinking we'll see a mass movement of evangelicals back to mainline denominations--perhaps many going all the way back (like I did)...to Catholicism.

Now, that would be an interesting trend.

[my debt of thanks to Mark P. Shea whose excellent book "By What Authority?" inspired this post]