Matthew Poole and continuators on John 4:42

42 And said unto the woman, Now we believe, not because of thy saying : for we have heard him our selves, and know that this is indeed the Christ, the Saviour of the world .

Several things may be the occasion of Faith, which are neither the principal efficient causes, nor the proper instrumental cause of it: The principal efficient cause of the Faith of these Samaritans, was undoubtedly the finger of God upon their Souls, enlightning their minds with the saving knowledge of the Gospel, and bowing their wills to the Obedience of it. The proper instrumental cause was their hearing the words of Christ, but the Occasion of this was what the Woman had told them; so as, tho they in a sense believed because of what she had said, because that occasioned their coming out to see, and hear Christ; yet the proper instrumental cause was their hearing Christ, God upon their hearing him working in their hearts, an ability, and a willingness to receive and to close with Christ. Thus the Church gives us the first occasion of receiving the Scriptures, and believing them to be the Word of God, we having them put into our hands by the Church, read them, and find such impresses and stamps of Divinity in them, that we conclude from our Reason very probably, that they are more than Humane Writings, but never firmly and fixedly receive them as such, until persuaded of it by the Holy Spirit.

These Samaritans do not onely own Christ as a Prophet, nor do they onely suspect that he must be the Messias, but they profess to know, that he was the Christ, the Saviour of the World.

Marginal references: Chap. 17.8.