Montanism is a heresy that arose in the Christian church during the second century under a man named Montanus who taught that God still reveals things to us today through extra-biblical means. This could be through dreams and visions or some other kind of neo-prophetic revelation.
After a several years of controversy, this heresy was condemned by the early church in 160 A.D. and has been deemed such ever since. However, in recent decades, what is known as neo-Montanism has emerged in various forms from “open, but cautious” continuationism to full blown charismatic tongue-babbling Pentecostals. What is clear, however, is that the covenant of grace has been administered, the canon of Scripture is complete and God no longer needs to send specific revelation. The charismatic sign-gifts have ceased and did so with the closing of the final book of the New Testament.
However, this doesn’t stop people from asserting this possibility and it generally stems from a lack of understanding of the Covenants. With each covenant administered by God followed specific revelation followed by a period of prophetic silence until the next covenant was revealed. There is no biblical support for the idea that God speaks to individuals in a personal way to give “personal” revelation for some kind of guidance in their personal life. God’s revelations have always been universal, with the intent of reaching andentire people. Yet, while Greear rightfully acknowledges that the Scriptures are sufficient, he tacitly affirms the possibility of this unbiblical practice in the video below.