WELS teaches that Jesus Christ is the eternal Son of God who existed before the incarnation. John 1:1-3 affirms that the Word (Logos) was with God and was God, and all things were made through him. Jesus' preexistence is coequal with the Father; he is not a created being but the eternally begotten Son of God.

The Old Testament theophanies and angelophanies are understood as manifestations of the preexistent Christ, the Son of God appearing in human or angelic form. The 'angel of the Lord' in many OT passages is interpreted as Christophanies—appearances of the Son before his incarnation. This reflects the principle of the communicatio idiomatum and the understanding that the divine persons, though distinct, are never separated in their operations.

Christ's preexistence undergirds his identity as the Creator and Sustainer of all things. The incarnation did not mark the beginning of his existence but rather his entering into human flesh and history while remaining fully divine. His preexistence establishes his divine authority, his capacity to be the unique Mediator and Redeemer, and his worthiness of worship and adoration.