Parallel
John 1:7
Patriarchal Greek New Testament (1904) · Berean Standard Bible
οὗτος ἦλθεν εἰς μαρτυρίαν, ἵνα μαρτυρήσῃ περὶ τοῦ φωτός, ἵνα πάντες πιστεύσωσι δι᾽ αὐτοῦ.
He came as a witness to testify about the Light, so that through him everyone might believe.