These things I have WRITTEN to you who believe in the name of the Son of God, that you may know that you have eternal life, and that you may continue to believe in the name of the Son of God.

1 John 5:13

The Word of God, the Bible, is the written evidence to those who believe that we might know that we have eternal life and that we might continue in the faith. John understood the power of the written Word. In the Gospel of John, he said the following:

And truly Jesus did many other signs in the presence of His disciples, which are not written in this book; but these are WRITTEN that you may believe that Jesus is the Christ, the Son of God, and that believing you may have life in His name.

John 20:30-31

This testimony of Jesus was written so that we might believe and in believing we might have life in His name! Eternal life is within the words that were written! How can we possibly know Him apart from that which is written? Some would suggest that all we need is the Spirit, but the Spirit apart from the Word is a formula for deception.
Paul declared:

But this I confess to you, that according to the Way which they call a sect, so I worship the God of my fathers, believing all things which are WRITTEN in the Law and in the Prophets.

Acts 24:14

In other words, Paul’s revelation only enhanced his understanding of what was written. The Law and the Prophets do not contradict the revelation of grace, they confirm it! So much so that Paul could devote an entire day to revealing Jesus to the Jewish leaders through what was written in the Old Covenant!

So when they had appointed him a day, many came to him at his lodging, to whom he explained and solemnly testified of the kingdom of God, persuading them concerning Jesus from both the Law of Moses and the Prophets, from morning till evening.

Acts 28:23

That is why Kenyon could confidently declare:
We become Christ-like in the measure that the Word prevails in us; in the measure we practice and live it. The Word is Christ revealed. The Word is God present with us, speaking the Living Message of the Loving Father God. _E.W. Kenyon

When Jesus confronted the devil in the wilderness, He defeated him by declaring, ‘It is WRITTEN.’ If Jesus could quote from Deuteronomy three times to defeat the devil in a face to face confrontation, wouldn’t it be wise for us to know what is written?

by Barry Bennett

For the word of God is living and active, sharper than any two-edged sword, piercing to the division of soul and spirit, of joints and marrow, and discerning the thoughts and intentions of the heart.

Hebrews 4:12