2Timothy:3:16: "All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness:"
2Peter:1:20&21: "Knowing this first, that no prophecy of the scripture is of any private interpretation. For the prophecy came not in old time by the will of man: but holy men of God spake as they were moved by the Holy Ghost."
I must quote these verses here. Without God's word the KJV bible we would not have a Christian church.
To use the bible to define what is the pillar of the church puts the bible in the first place above the church.
Jesus sent the Comforter to teach us all things, bring to remembrance whatever He said, to guide us into all truth, to reprove the world of sin and righteousness and judgement John 14-16. If everyone understood John 14-17 there would be only one denomination and one translation of God's holy word the KJV bible.
My understanding has little to nothing to do with what God reveals to me. IF we let the Holy Spirit work through us He will reveal all truth He wants us to have at that moment. We are told in 1John:2:27: "But the anointing which ye have received of him abideth in you, and ye need not that any man teach you: but as the same anointing teacheth you of all things, and is truth, and is no lie, and even as it hath taught you, ye shall abide in him." To attend church for fellowship and to get a spiritual shot in the arm is good, but to rely on any pastor, evangelist, preacher, teacher, priest, or whole denomination will leave us very disappointed. We are told to study to show ourselves approved unto God, but what is it we are to study? Church doctrine created by the church "fathers"? Are we to put the interpretation of God's word on man in the form of a church? We are admonished to do as the Bereans did Acts 17:11. When they heard the word they went home and studied it out to make certain what was taught was the truth. We all should do this. Far too many people who profess the Name of Jesus rely totally on their church or denomination to lead them to heaven, and that will never happen. No denomination has a monopoly on salvation. God has people in all denominations.
Back to your question, is it the church or God's holy word the KJV bible??? If the church is the pillar then which one? There are far too many denominational differences to rely on any denomination. The word of God is our ONLY salvation. It is the ONLY place we can find the true gospel of Jesus. The first true apostolic church had to be all of one mind, in the same place before they could receive the Holy Spirit. Same goes for God's church today. We, as Christians must all be in unity with the truth, the truth that each of us have been given by the Holy Spirit. If the Holy Spirit is leading everyone will be in unity of faith and doctrine.