Oneness Pentecostals affirm that the divine nature in Jesus Christ — which they identify as God himself, the Father — is eternal and pre-existent. However, the Son as such — meaning the human nature, the embodied expression of God — began at the incarnation in Mary's womb. This requires distinguishing carefully between what Oneness theology means by 'Son.'

In Oneness theology, 'the Son of God' refers primarily to Jesus' human nature — the divine being clothed in humanity. Before the incarnation, there was no Son; there was only the eternal Father God. Texts that appear to refer to Christ's pre-existence — such as John 1:1 ('the Word was with God') — are interpreted as referring to the divine plan or purpose (the Logos as divine wisdom or purpose pre-existing in God's mind) rather than to a pre-existent divine person.

This position differs from both Trinitarianism (which affirms the eternal pre-existence of the Son as a distinct divine person) and from some anti-Trinitarian views (like Christadelphians) that deny any pre-existence of Christ's divine identity. In Oneness theology, the pre-existent one is God the Father himself — the same one who became the Son at the incarnation. The name 'Jesus' fully identifies and names this eternal God who took on flesh.