Two paragraphs from John Calvin’s Second Sermon on Ephesians (he preached 48 sermons in his Ephesians series).
I said just now that the preaching of His Word is a singular benefit to us. And that is the reason that it is said so often in the Law and the Prophets that God has not dealt with any other nation as He dealt with the line of Abraham, in that He vouchsafed (gave a gracious gift) to choose and adopt them, to which the law gave sure testimony. So then the children of Israel were exhorted to praise God because He had vouchsafed to give them His law (Deut. 4:7), and, in the meanwhile, had let the poor Gentiles alone as people that did not belong to Him after the same fashion.
But it is yet a far greater and more special privilege when He makes us profit by that Word. For it is certain that our ears might be assailed daily with the things that should be told us and that we would never be the better for it, until God speaks to us by His Holy Spirit within us.
In this manner, then, God shows us a double grace. The one is when he raises up men to preach the gospel to us, for no man is meet and sufficient to do it of himself. It is therefore necessary that God should send those who call us to Him and offer us the hope of salvation. But yet, for all of that, let us note well that we cannot believe unless God reveals Himself to us by His Holy Spirit and speaks to our hearts by the Holy Spirit, in addition to speaking to our ears by the mouth of man.