Now, then, note that, if this be our Lord’s meaning here, Jesus Christ plainly anticipated that, after His departure from Earth, there should be a development of Christian doctrine. We are often taunted with the fact, which is exaggerated for the purpose of controversy, that a clear and full statement of the central truths which orthodox Christianity holds is found, rather, in the apostolic epistles than in the Master’s words, and the shallow axiom is often quoted with great approbation: “Jesus Christ is our Master, and not Paul.”
I do not grant that the germs and the central truths of the gospel are not to be found in Christ’s words, but I admit that the full, articulate statement of them is to be found, rather, in the servant’s letters, and I say that that is exactly what Jesus Christ told us to expect – that, after He was gone, words that had been all obscure and thoughts that had been only fragmentarily intelligible would come to be seen clearly and would be discerned for what they were. The earlier disciples had only a very partial grasp of Christ’s nature. They knew next to nothing of the great doctrine of sacrifice. They knew nothing about the resurrection. They did not, in the least, understand that He was going back to heaven. They had but glimmering conceptions of the spirituality or universality of His kingdom. While they were listening to Him at that table, they did not believe in the atonement, but they dimly believed in the divinity of Jesus Christ. They did not believe in His resurrection. They did not believe in His ascension. They did not believe that He was founding a spiritual kingdom, a kingdom that was to rule over all the world until the end of time. None of these truths were in their minds. They had all been in germ in His words. And, after He was gone, there came over them a breath of the teaching of the Spirit and the unintelligible flashed up into significance.
The history of the church is the proof of the truth of this promise and, if anybody says to me, “Where is the fulfillment of the promise of a Spirit who will bring all things to your remembrance?,” I say, “Here, in this book!” These four gospels, these apostolic epistles, show that the word which our Lord here speaks has been gloriously fulfilled. Christ anticipated a development of doctrine, and it casts no slur or suspicion on the truthfulness of the apostolic representation of Christian truths that they are only sparsely and fragmentarily to be found in the records of Christ’s life. – Alexander Maclaren (1826-1910), from a meditation on John 14.25-26.