"Since God’s special grace is the person and work of Christ applied by the Holy Spirit, the means of grace must be anchored to the doctrine of revelation. . . 

This is a cardinal tenet of Reformed theology—people hear the gospel through the preaching of the Word and are in this way apprehended by Christ through the power of the Holy Spirit.

The means by which God reveals Christ, and thereby His grace, centers principally on the Word of God. The book of Hebrews shows the link between revelation, christology, and eschatology: “God, who at various times and in various ways spoke in time past to the fathers by the prophets, has in these last days spoken to us by His Son” (Heb. 1:1–2a). God’s Word is the only means by which He reveals His special grace, by which He reveals Christ in the last days. This is a cardinal tenet of Reformed theology—people hear the gospel through the preaching of the Word and are in this way apprehended by Christ through the power of the Holy Spirit. Again, just as God spoke the creation into existence (Gen. 1:1; Heb. 11:3), so now He creates the new heaven and earth and calls into existence things that do not exist through His Word (cf. Rom. 4:17). In this manner, the Word of God is the chief means of grace. Through the reading or preaching of the Word, God sets forth the person and work of Christ, then applies them to the auditor by the power of the Holy Spirit."

~Word, Water, and Spirit: A Reformed Perspective on Baptism, 275-276