Theophylact of Ohrid
Catena Aurea · Johannesevangelium 1
There was a man sent from God, whose name was John. The same came for a witness, to bear witness of the Light, that all men through him might believe. He was not that Light, but was sent to bear witness of that Light.
Though some however might not believe, he is not accountable for them. When a man shuts himself up in a dark room, so as to receive no light from the sun’s rays, he is the cause of the deprivation, not the sun. In like manner John was sent, that all men might believe; but if no such result followed, he is not the cause of the failure.