The Holy Spirit is our true minister, our communication with God.
The commonly accepted doctrine of sola scriptura teaches that the Bible is the the sole infallible source of authority for Christian faith and practice. While the HS does help us with understanding the Word of God, He cannot teach anything that contradicts the Word of God. There are some groups out there that claim to hear directly from God on a regular basis, but some of this does not line up with the Bible and thus heretical.
The Bible is the last word for us from God. It cannot be added to or diminished as per Deut. 4:2
