The gospel is trinitarian because what God does reflects who God is (Eph. 1:3-14). Preaching must reflect the missionary goal of the Father. Do we seek worshipers through preaching sermons and do we seek to worship when hearing them? Preaching must promote dependence on the Spirit to produce sincere worshipers. Do we acknowledge the necessity of the Spirit’s inward work in us in preaching and hearing sermons? Preaching must aim to bring people to worship the Father through Christ, who reveals himself in Scripture.
Every divine work reflects God’s Triunity. This means that if we want to understand what God is doing in our lives we must begin with who God is. The Father always acts through his Son and by his Spirit. We come to the Father, by the Spirit, through the Son (Eph. 2:18). Preaching in relation to other biblical topics is like the relationship of countries to continents and continents to the world. Preaching must fit into the broader picture of the plan and work of the triune God.
John 4:21-24 gives us insight into the theological world in which preaching is found by describing the goal of evangelism. There we find Jesus telling the woman at the well, “Woman, believe Me, the hour is coming when you will neither on this mountain, nor in Jerusalem, worship the Father. You worship what you do not know; we know what we worship, for salvation is of the Jews. But the hour is coming, and now is, when the true worshipers will worship the Father in spirit and truth; for the Father is seeking such to worship Him. God is Spirit, and those who worship Him must worship in spirit and truth” (John 4:21-24). Since the Father is seeking people to worship him in Spirit and in Truth, preaching should aim to produce people who worship the Father by the Spirit through the Son. Relating preaching to the work of the Trinity is important because it ties together what preaching is, its necessity, its manner, and its aims in light of the doctrine of God, which is the center of the theological universe of Scripture.
First, the Father is seeking worshipers (v. 23). Worship is the primary purpose of life and worship is the primary context of this passage. Jews and Samaritans had no dealings with one another (v. 9) because they disagreed sharply over how to worship God. Jesus promised to give the woman of Samaria living water that would satisfy her thirsty soul, giving her eternal life (v. 10-14). When she wanted this water, Jesus confronted her with the fact that she had had five husbands (v. 15-18). By this, the woman knew that Jesus was a prophet (v. 19). As such, he was suited to teach her how to worship the Father. As they stood at the foot of the place of Samaritan worship, which embodied the Jewish/Samaritan division, she went to the heart of the matter by asking Jesus where the proper place of worship was (v. 20). She was not changing the subject. Jesus responded that her question would become irrelevant because all people would soon worship the Father in every place rather than on one mountain (v. 21). The second thing that he said was that Jewish worship was right and Samaritan worship was wrong (v. 22). Worship belonged to the Jews because salvation belonged to the Jews. To them were committed “the oracles of God” (Rom. 3:2). In God’s light we see light (Ps. 36:9), but worship that is not informed by Scripture lies under the darkness of ignorance. The Father is seeking worshipers. Salvation is the means to this end. Preaching must match the Father’s missionary aim.