John 1:7 - Ellicott's Commentary On The Whole Bible

For a Witness. — Stress is laid upon the work of John as “witness.” This was generally the object of his coming. It was specially to “bear witness of the Light.” The purpose of testimony is conviction “that all men through him might believe,” i.e., through John, through his witness. Compare with this purpose of the Baptist’s work the purpose of the Apostle’s writing, as he himself expresses it in the closing words of John 20; and also the condition and work of the Apostleship, as laid down by St. Peter at the first meeting after the Resurrection (Acts 1:21-22). The word “witness,” with its cognate forms, is one of the key-notes of the Johannine writings recurring alike in the Gospel the Epistles, and the Apocalypse. This is partly concealed from the general reader by the various renderings “record,” “testimony,” “witness,” for the one Greek root; but he may see by consulting any English concordance under these words, how frequently the thought was in the Apostle’s mind. See especially Revelation 1:2; Revelation 1:9, Notes.