John 1:30 repeats the same testimony verbatim, confirming John's identification of Jesus as the preexistent one.

John 1:29-34 expands John's witness with the Lamb of God and Spirit descent — the content behind the summary in John 1:15.

John 1:8 clarifies John was not the light but a witness; John 1:15 exemplifies that witness by pointing to Jesus.

John 1:7 introduces John's role as witness to the light; John 1:15 records his specific testimony about Jesus' preexistence.

John 1:1 establishes the Word's eternal existence, grounding John 1:15's claim that Jesus existed before John.

In John 1:27, John repeats his humility: he is unworthy to untie Jesus' sandals, reinforcing the priority of the pre-existent One.

John 1:2 restates the Word's eternal coexistence with God, reinforcing the preexistence that John 1:15 points to.

John 3:26-36 continues John's witness, emphasizing Jesus' supremacy and preexistence — echoing the same themes from John 1:15.

John 17:5 reveals Jesus's pre-incarnate glory with the Father, substantiating the preexistence asserted in John 1:15.

John 8:58 records Jesus's own claim to preexistence ('before Abraham, I am'), confirming John 1:15's testimony.

John 5:33 quotes Jesus citing John's witness as truthful — directly referencing the testimony recorded in John 1:15.

In John 3:31, John contrasts earthly and heavenly origin, echoing the pre-existence and superiority of Jesus over him.

Revelation 2:8 identifies Jesus as 'the first and the last, who died and came to life' — reinforcing his pre-existence and eternal life.

Philippians 2:6 affirms Christ's pre-incarnate divine nature ('form of God') — explaining the 'before me' as existence in equality with God.

Philippians 2:7 describes Christ's self-emptying in becoming human — showing how the pre-existent One could come 'after' John in time.

Colossians 1:17 explicitly states Christ is 'before all things' — echoing John's testimony that Jesus was before him.

Revelation 1:17 has Christ declare 'I am the first' — directly affirming his pre-existence which John testified to.

Isaiah 9:6 prophesies a child who is 'Mighty God' and 'Everlasting Father' — the pre-existent divine Messiah John testifies about.

Luke 3:16 similarly records John's proclamation of Jesus's greater power and the coming Spirit baptism, paralleling the testimony.

Mark 1:7 echoes John's testimony of unworthiness to untie Jesus's sandals, emphasizing Jesus's superior authority.

Matthew 3:13-17 shows John's reluctance to baptize Jesus, demonstrating his acknowledgment of Jesus's greater status as testified.

Matthew 3:11 records John's same declaration that Jesus is mightier and baptizes with the Holy Spirit, reinforcing his superior rank.

Micah 5:2 predicts the Messiah's origin 'from of old, from ancient days' — directly supporting John's claim that Jesus existed before him.

Luke 1:77 describes John's role to give knowledge of salvation through remission of sins. This reveals the purpose behind his testimony about Jesus's supremacy.

Mark 1:3 quotes Isaiah about a voice crying in the wilderness to prepare the Lord's way. This directly identifies John the Baptist, supporting his role as witness to Jesus.

Acts 19:4 quotes John's message about the coming Christ, directly reinforcing the testimony of John 1:15.

Matthew 11:11 says John is the greatest born of women yet the least in the kingdom is greater — echoing John's claim that the one after him is preferred. Parallel teaching on John's inferiority to Christ.

Malachi 3:1 predicts a messenger preparing the way for the Lord. This identifies John the Baptist as that forerunner, grounding his testimony about Jesus's preexistence.

Hebrews 13:8 declares Jesus Christ the same yesterday, today, forever — reinforcing his eternal existence implied by 'he was before me'.

Acts 13:24 describes John's preparatory baptism, providing historical context for his role as the forerunner mentioned here.