John Calvin Commentary John 1:47

"Jesus saw Nathanael coming to him, and saith of him, Behold, an Israelite indeed, in whom is no guile!" — John 1:47 (ASV)

Behold, one truly an Israelite. It is not on Nathanael’s own account that Christ bestows this commendation on him, but through him, He presents a general doctrine. For, since many who boast of being believers are very far from actually being believers, it is very important that some mark be found for distinguishing the true and genuine from the false.

We know how haughtily the Jews gloried in their father Abraham and how presumptuously they boasted of the holiness of their descent; yet there was scarcely one in a hundred among them who was not utterly degenerate and alienated from the faith of the Fathers. For this reason, Christ, in order to tear the mask from hypocrites, gives a short definition of a true Israelite and, at the same time, removes the cause for offense that would later arise from the wicked obstinacy of the nation.

For those who wished to be regarded as the children of Abraham and the holy people of God were soon to become the deadly enemies of the Gospel. So that no one might be discouraged or alarmed by the impiety generally found in almost all ranks, He gives a timely warning that among those who assume the name of Israelites, there are few who are true Israelites.

Again, as this passage contains a definition of Christianity, we must not treat it lightly. To sum up Christ’s meaning in a few words, it should be observed that deceit is contrasted with uprightness and sincerity; so that He calls those persons sly and deceitful who are called in other parts of Scripture double in heart (Psalms 12:2); nor is it only that gross hypocrisy in which those who are conscious of their wickedness pretend to be good men, but also another inward hypocrisy, when people are so blinded by their vices that they not only deceive others but themselves.

So then, it is integrity of heart before God and uprightness before men that makes a Christian; but Christ chiefly points out that kind of deceit which is mentioned in Psalm 32:2. In this passage, ἀληθῶς (truly) means something more than certainly. The Greek word, no doubt, is often used as a simple affirmation; but as we must understand a contrast here between the fact and the mere name, he is said to be truly who is in reality what he is supposed to be.