But Machen was not finished. What remains is the highest and the most impor­tant institution of all—the church of Christ. Indeed, the entire thesis of Christianity and Liberalism comes to bear on the final chapter as Machen urges the recovery of a high view of the church. Judging from the current state of the church even among those who claim to love this book, however, we may wonder how many have carefully read this final chapter.

Machen begins by challenging a thin form of community that is premised on the “universal brotherhood of man.” Clear doctrinal boundaries are required to sustain a genuine fellowship of brothers and sisters in Christ, simply because, as he clearly demonstrated in the preceding pages, liberalism is a complete departure from Christianity. “The greatest menace to the Christian Church today,” he wrote, “comes not from the enemies outside, but from the enemies within; it comes from the presence within the church of a type of faith and practice that is anti-Christian to the core.” Consequently, “a separation between the two parties in the church is the crying need of the hour.” Machen’s “straightforward” and “above board” appeal earned him the respect of “friendly neutrals” (as the secular journalist H.L. Mencken described himself as he followed the debate closely).

How would this separation take place? At the time the book was published, what seemed the most likely prospect—from both sides of the divide—was that a small number of liberals would leave the church. And Machen invited them to take this step of honesty. But he also anticipated another scenario, wherein conservatives would be forced to leave the church. A decade later, this is how the struggle would play out, as he himself was defrocked for the high crime of “disloyalty” to the boards of the church that were beset with modernism. Faithfulness to their ministerial calling compelled him and his allies to bear this cross.