A mystic may inconsistently claim reliance on Scripture, which he may even claim to be infallible. But his actions, which speak louder, tell us that he deems Scripture to be insufficient. He needs a new revelation from God. He needs a new experience, etc.
The danger with mysticism is that the ideas sound true and almost Scriptural at times. Many people appeal to language like the “Spirit’s witness.” Appeals are made to gifts of the Spirit. And of course, we all understand the importance of having a living experiential knowledge of the truths we believe. But that is exactly where things get dicey.
We have all heard wonderful testimonies of God’s work in someone’s life. We know the stories of ex-gang members of former drug dealers who have been converted. These stories are wonderful. They glorify God and they certainly have a place in the life of the Church. But, that place is not evangelism. Putting your personal experience with Jesus into the center of your evangelism, and urging others to come to Christ based on the hope that they too may experience something similar, is no different than the Mormon missionaries who tout their “burning in the bosom.” That experience, whatever it may be, is absolutely unverifiable. The only thing I have to go on is the testimony of the person claiming it. In matters of eternal salvation or damnation, that simply isn’t good enough.
Notice that in the New Testament the Apostles NEVER use personal experiences or testimonies as part of their evangelism. They shared the historical facts of Christ’s birth, life, death and resurrection. They proclaimed the historicity of these events and their occurrence as fulfillments of Old Testament prophecies.
This is not to say that in the history of mankind God has never had direct access to a human soul to proclaim truth. The Bible itself is a result of such occurrences. But the Bible itself tells us that such occurrences were rare and were restricted to a handful of people – prophets and apostles. Hebrews 1:1-2 tells us, “God, who at sundry times and in divers manners spake in time past unto the fathers by the prophets, hath in these last days spoken unto us by his Son.” Christ is God’s final word.
Charles Hodge wrote, “The common doctrine of the Christian Church is, that God has at sundry times and in divers manners spoken to the children of men; that what eye hath not seen, or ear heard, what never could have entered into the heart of man, God has revealed by his Spirit to those whom He selected to be his spokesmen to their fellow-men; that these revelations were authenticated as divine, by their character, their effects, and by signs and wonders, and divers miracles and gifts of the Holy Ghost; that these holy men of old who spake as they were moved by the Holy Ghost, communicated the revelations which they had received not only orally, but in writing, employing not the words which man’s wisdom teacheth, but which the Holy Ghost teacheth; so that we have in the sacred Scriptures the things of the Spirit recorded in the words of the Spirit; which Scriptures, therefore, are the Word of God, — i.e., what God says to man; what He declares to be true and obligatory, — and constitute for his Church the only infallible rule of faith and practice.” Systematic Theology Volume 1, Chapter 4.
Regardless of the apparent innocence of the mystical experience or its apparent agreement with Scripture, it is to be distrusted and discarded because it claims to be another revelation from God, making Scripture insufficient. If Scripture is sufficient, what is the need of these other revelations? No amount of mental gymnastics can evade that question.
Scripture is the final and ONLY revelation God has given to the Church. Later in life when Peter recalls the incident on the Mount of Transfiguration, he remembers how Christ’s appearance was changed, how the cloud of God’s glory overshadowed them, and how God’s voice audibly spoke. Yet, he says concerning Scripture, “We have also a more sure word of prophecy,” (2 Peter 1:19). Let that sink in a moment.