"Every other variant of Christianity is a rivulet which goes its own way until it eventually disappears."

At the end of a lengthy discussion by  Retired United Methodist Church bishop Timothy W. Whitaker on "Christianity & Liberalism" by J. Gresham Machen (1881-1937) reprinted at Juicy Ecumenism came the following observation,

"If one believes that the kind of Christianity which is God’s cause in the world is the Christianity which is faithful to the apostolic witness as it has been received in the catholic tradition of the church, then one would view liberalism as a variant of Christianity which erodes the substance of the apostolic and catholic faith and enervates the mission of the church. Liberals tend to see their version of Christianity as the vanguard of the future, which is an odd conceit in light of how few liberal Christians there are in the context of global Christianity. It is more plausible that the historic, orthodox, apostolic and catholic faith is the future of Christianity as well as its past, and it is the great river of tradition which flows through time moving in the current of the Holy Spirit. Every other variant of Christianity is a rivulet which goes its own way until it eventually disappears."

If he were alive today, Machen would probably not have to make any corrections to his 1923 book (found here) because he was drawing his wisdom from that great river of tradition which is the past and the future of Christianity.

I understand that the river of tradition can get polluted from many sources along the way, so it needs river keepers stationed all along its course to filter out large debris and smaller contaminants.

The thought of liberal variants as rivulets that will go their own way and eventually disappear gives me hope, a hope tempered by the knowledge that new rivulets with which we shall have to contend will always be appearing.