Oneness theology denies the Trinity and teaches that God is a single person who manifests himself in different modes at different times: now as Father, now as Son, now as Holy Spirit. According to this view, however, these three manifestations never correspond to three distinct persons acting simultaneously, as Scripture reveals. This doctrine, technically called modalism, traces back to Sabellius in the third century, and was rejected by the early church at that time, in a debate that church history long considered essentially closed. Today, however, it remains present in groups such as the UPCI (United Pentecostal Church International) worldwide, and in Brazil in the Igreja Voz da Verdade (Voice of Truth Church) and similar movements.
The baptism of Jesus presents, with striking clarity, three distinct persons acting simultaneously in the same scene: the Son being baptized in the water, the Spirit descending like a dove, and the Father's voice speaking from heaven (Matt 3:16-17). This reality does not fit the logic of Oneness theology, which would have to interpret the scene as an alternation of manifestations or some kind of division of roles that does not match what the biblical text presents.
An error regarding who God is rarely stays confined to the doctrine of the Trinity. When the understanding of God's nature is distorted, other areas of theology are affected as well, especially the doctrine of salvation, prayer, and the very assurance of the Christian faith. Jesus commanded his disciples to make disciples of all nations, “baptizing them in the name of the Father and of the Son and of the Holy Spirit” (Matt 28:19). This is an explicit trinitarian formula, one that Oneness theology must reinterpret in a strained way to preserve the internal coherence of its doctrine.
Dialogue with adherents of Oneness theology requires doctrinal firmness, but also genuine pastoral care for the person standing before us. A cold, distant theological correction is not enough. Paul closed his second letter to the Corinthians with a blessing that expresses, simply and naturally, the communion of the three persons of the Trinity: “The grace of the Lord Jesus Christ and the love of God and the fellowship of the Holy Spirit” (2 Cor 13:13). This greeting presents a personal distinction between Father, Son, and Holy Spirit that modalism struggles to explain without resorting to artificial interpretations.
Read Matthew 3:16-17 and carefully observe the three distinct agents present simultaneously in the scene of Jesus' baptism. If you know someone who belongs to a Oneness church, calmly prepare a sincere question about who Jesus is for that person, without immediately launching into a doctrinal confrontation. Also memorize 2 Corinthians 13:13 as a clear, natural biblical summary of the full communion between the three persons of the Trinity.
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