Critics of the doctrine of the Trinity often complain that the idea is not biblical because the word Trinity does not appear in the Bible. Yet even though the term Trinity is not found in Scripture, the doctrine still holds true, as the apostles and the prophets everywhere assume the teaching that the word Trinity summarizes.
Paul’s words of praise in Ephesians 1:3–14 demonstrate this truth, as he presents clearly the one work of salvation by the three persons of the triune Godhead. We see in verses 3–6 that the Father planned redemption, having predestined His people to eternal life in Christ. The Son of God carried out the work necessary to secure the salvation our Father planned and promised. Jesus Christ, the God-man who is the perfect union of the second person of the Trinity with our humanity, shed His blood to bring us forgiveness and, due to His obedience, is exalted as King over all (vv. 7–12). God the Holy Spirit seals the work of Christ to us, applying the benefits of salvation and marking us off as our Creator’s special possession (vv. 13–14). Each person works distinctively to bring salvation, yet harmony pervades the process, for the works of the Trinity are undivided — all of the persons of the Godhead work together to achieve the same end and never stand at cross purposes with one another. God, therefore, is irreducibly three in person — Father, Son, and Spirit — and one in essence.
Verse 10 explains that the goal toward which the persons of the Trinity are working is the fulfillment of the divine plan for all things to be united in Christ Jesus in the fullness of time. The apostle is telling us that the Holy Trinity will set Jesus over all things at the time determined from all eternity; one day all of creation will acknowledge His reign and bow to Him. At this point in history, Christ is indeed seated on His throne (Acts 2:29–36), but His reign is largely invisible. The Devil continues to rebel, and the nations refuse to honor their rightful sovereign (Eph. 6:11–13; 1 Peter 5:8; Rev. 17). Yet the trouble that ensues from this refusal to bow to Christ will not last forever. Dr. R.C. Sproul writes that “God’s appointed plan for the universe is to bring all things on heaven and on earth together, under one head. The goal of creation is neither chaos nor disharmony but unity, and the point of unity will be his anointed king” (The Purpose of God: Ephesians, p. 30; hereafter PGE).