John Calvin Commentary John 12:44

"And Jesus cried and said, He that believeth on me, believeth not on me, but on him that sent me." — John 12:44 (ASV)

And Jesus cried. The purpose of Christ, in this statement, is to encourage his followers to a proper and unshaken steadfastness of faith; but it also contains an implied reproof, by which he intended to correct that perverse fear. The cry is expressive of vehemence, for it is not a simple doctrine, but an exhortation intended to stir them more powerfully.

The statement amounts to this: that faith in Christ does not rely on any mortal man, but on God; for it finds in Christ nothing but what is divine, or rather, it beholds God in his face. Therefore, he infers that it is foolish and unreasonable for faith to be wavering or doubtful, for it is impossible to offer a greater insult to God than not to rely on his truth.

Who is it then that has duly profited by the Gospel? It is he who, relying on this confidence, that he does not believe men but God, quietly and steadily contends against all the machinations of Satan. If, then, we are to render to God the honor due to him, we must learn to remain firm in faith, not only even if the world were shaken, but even if Satan should disturb and overturn all that is under heaven.

He that believeth on me believeth not on me, but on him that sent me. Believers are said not to believe on Christ when they do not fix their whole attention on his human countenance. Comparing himself with the Father, he instructs us to look at the power of God, for the weakness of the flesh has no firmness in itself.

When we later find him exhorting the disciples to believe on him, it will be in a different sense; for, in that passage, God is not contrasted with man, but Christ is brought forward with all his gifts and graces which ought to be sufficient for upholding our faith.