Is Textual Criticism Theologically Safe?

Why do so many Evangelicals study textual criticism? (Besides because it’s the best.) Here’s one answer that I have come across several times now:

“Lower” textual criticism, as it is called, is often regarded as a pedantic prerequisite to “higher” historical-literary scholarship. Indeed, many believing Christian scholars choose New Testament textual criticism as their milieu just because it is blessedly boring and does not threaten their religious beliefs. But as the Johannine comma reminds us, it is the lower criticism, rather than its more glamorous younger sibling, that shows the biblical text to be contingent and thus subject to history. In other words, it is textual criticism that first humanized the word of God. —Raphael Magarik (source)

Speaking for myself, the theological cause-and-effect actually worked the other direction. The need for textual criticism itself posed a certain threat to my faith early on and that partly pushed me to pursue the field. The more I studied it, the less it posed a problem for me theologically. Before long, of course, the shear joy of textual criticism won me over! But I certainly didn’t set out in this field because I felt it was less threatening. Quite the opposite.