Machen argued that
Liberal Christianity constitute a distinct religion, since it denied
substitutionary atonement.[3] However, its true nature was, according to Machen, "hidden by the duplicitous use of traditional terms and categories by liberal clergy."[4] Machen wrote,[5][6][7]
The liberal attempt at reconciling Christianity with modern science has really relinquished everything distinctive of Christianity, so that what remains is in essentials only that same indefinite type of religious aspiration which was in the world before Christianity came upon the scene.
Iain H. Murray calls Christianity and Liberalism "one of the most important books of all times".[8][9]