Since I was recently accused of being crypto-Reformed I thought I might as well go the whole hog and recommend a book by a Reformed author. "Christianity and Liberalism" (published 1923) is the book and J. Gresham Machen* (1881-1937) is the author. I've been re-reading it while on holidays (as I get older I find it less important to read "the latest", and more beneficial to read and re-read what is best from the past). Machen was professor of New Testament at Princeton until 1929, when he was forced out of that position - and eventually his church - as a consequence of his opposition to theological modernism. His early death came as a result of contracting pneumonia in the midst of a North Dakota winter while honouring speaking engagements designed to bolster support for a new, creedally orthodox Presbyterian church body in the northern US. Among his last words were apparently, "I’m so thankful for the active obedience of Christ. No hope without it." That does indeed strike me as something a pious Calvinist might say, whereas a Lutheran would surely be more focussed on and grateful for Christ's passive obedience.
Be that as it may...this book is an incisive study of the differences between orthodox Christianity and liberal Christianity on several crucial doctrinal topics - God, humanity, the Bible, Christ, salvation and the church. This was actually one of the first Christian books I ever read, as I was trying to figure out why the Anglican Church of my place and time did not believe or teach the 39 Articles. I'll forever be grateful to Machen for inocculating me against liberalism. Of course, there's been a lot of water under the bridge since 1923, but it's surprising how little of what Machen has written could be discarded as irrelevant today, which is probably why this book has remained constantly in print for 80+ years while other books on the same subject from the period have passed into oblivion.
Well, having recommended the book, let me share from it something of Machen's understanding of the grammar of the Gospel, a concern for which my own New Testament Greek teacher, Dr Greg Lockwood, tried to drum into undergraduate seminarian heads:
"Here is found the most fundamental difference between liberalism and Christianity -liberalism is altogether in the imperative mood, while Christianity begins with a triumphant indicative; liberalism appeals to man's will, while Christianity announces, first, a gracious act of God."
J. Gresham Machen, Christianity and Liberalism, Eerdmans reprint, n.d., p47
I guess even the Reformed get it right sometimes ;0)
You can get the book in paperback for c. AUS$16.95 at the usual places, and New Reformation Press (see link under Lutheran publishers in right-hand column) have for download a helpful outline by Dr Rod Rosenbladt (he must be crypto-Reformed too.) Reformed Audio.org apparently have a free PDF download of the book, along with a free audio file of the entire book, but I haven't checked that out (click on the post title to view a video intro to the book from this organisation).
* Pronounced may'chen btw. For a long time I thought it was may'ken - such embarrasing mispronunciations are the bane of the autodidact's life...I still can't pronounce Sasse correctly.