“The Bible has many human authors, but one divine Author speaks through them all: the triune God who draws near to us in the Mediator. Though Paul wrote his letters, he insists, ‘Christ is speaking in me’ (2 Cor. 13:3), and, ‘The things that I write unto you are the commandments of the Lord’ (1 Cor. 14:37).
Therefore, in the Bible, we continue to hear the voice of Christ today. In a manner of speaking, the whole Bible comes to us in red letters.
This makes reading the Bible and hearing it preached a wonderfully personal encounter with Christ. Christ said that the Good Shepherd calls His sheep, and ‘the sheep hear his voice… and the sheep follow him: for they know his voice’ (John 10:3-4).
Christ did not refer here merely to His earthly ministry to Israel, when people literally did hear His human voice. He included the calling of Gentiles: ‘Other sheep I have, which are not of this fold: them also I must bring, and they shall hear My voice; and there shall be one fold, and one shepherd’ (John 10:16).
This is the assurance of Christ’s people: ‘My sheep hear My voice, and I know them, and they follow Me: and I give unto them eternal life; and they shall never perish, neither shall any man pluck them out of My hand (John 10:27-28).
Whenever we prepare to read or hear God’s Word, we should say to ourselves, ‘I am about to hear the voice of Jesus.’ Calvin said, ‘When the pure doctrine of the gospel is preached, it is just as if He Himself spoke to us and were living among us.'”
–Joel R. Beeke and Paul M. Smalley, Reformed Systematic Theology, Volume 2: Man and Christ (Wheaton, IL: Crossway, 2020), 2: 963-964.