The proper ground for believing a thing is not that the church or reason says it. Both these authorities may err and, in any case, it is not to them that God has told us to go for authoritative indications of His mind. The proper ground for believing a thing is that God says it in His written Word, and a readiness to take God’s Word and accept what it asserts in the Bible is, thus, fundamental to faith.
Not that church tradition is unimportant. On the contrary, it yields much valuable help in understanding what Scripture teaches. The Spirit has been active in the church from the first, doing the work that He was sent to do: guiding God’s people into an understanding of revealed truth. The history of the church’s labor to understand the Bible forms a commentary on the Bible which we cannot despise or ignore without dishonoring the Holy Spirit. Tradition may not be lightly dismissed, but neither may it be made a separate authority apart from Scripture. Like every commentary on the Bible, it must itself be tested and, where necessary, corrected by the Bible which it seeks to expound.
Nor may reason be viewed as an independent authority for our knowledge of God’s truth. Reason’s part is to act as the servant of the written Word, seeking, in dependence on the Spirit, to interpret Scripture scripturally, to correlate its teaching, and to discern its application to all parts of life. We may not look to reason to tell us whether Scripture is right in what it says (reason is not, in any case, competent to pass such a judgment); instead, we must look to the Scriptures to tell us whether reason is right in what it thinks on the subject with which Scripture deals. – J. I. Packer (born in 1926)