In 1923, J. Gresham Machen wrote a groundbreaking book called Christianity and Liberalism. A leader in the conservative movement within the Presbyterian Church, Machen wrote the book to demonstrate the fundamental difference between biblical Christianity and liberal Christianity. Looking back on the controversy his book provoked, he wrote this assessment:
The issue in the Church of the present day is not between two varieties of the same religion, but, at bottom, between two essentially different types of thought and life. There is much interlocking of the branches, but the two tendencies, Modernism and supernaturalism, or (otherwise designated) non-doctrinal religion and historic Christianity, spring from different roots. In particular, I tried to show that Christianity is not a “life,” as distinguished from a doctrine, and not a life that has doctrine as its changing symbolic expression, but that—exactly the other way around—it is a life founded on a doctrine.
That last phrase deserves special notice: “a life founded on a doctrine.” Today many people who claim to know Jesus don’t believe the Bible is the Word of God. There are New Age types who say they love Jesus, but the Jesus they claim to love is not the Jesus of the Bible. We want to help people find a “personal relationship with Jesus Christ.” But we do not mean a “personal relationship” apart from the Christ of the Bible. We mean a true personal relationship with the Christ revealed in the Bible. Salvation is life-changing precisely because it is a “life founded on a doctrine.”