John Calvin Commentary John 5:34

"But the witness which I receive is not from man: howbeit I say these things, that ye may be saved." — John 5:34 (ASV)

I do not receive testimony from men. Yet it was not in vain that God chose Christ to be a witness to him, and Christ himself declares, on another occasion, that the disciples will be his witnesses: You shall be witnesses to me, both in Jerusalem, and in all Judea, and in Samaria, and unto the uttermost part of the earth (Acts 1:8).

I reply, Christ makes use of the testimony of John, not because he needs it, but insofar as it is advantageous for us to receive some confirmation from it. Men borrow testimony from one another because they cannot do without that assistance. The case is different with God and Christ. For if philosophers assert that virtue has no need of foreign aid, what does man have in himself to lend support to the truth of God?

And Christ immediately adds that he produces the testimony of John for their sake: these things I say that you may be saved. By this statement he means that it is not so much out of concern for himself as from a desire to promote the benefit of men that he raises up the heralds of his Gospel, through whom he testifies to us concerning his will.

In this we also see a striking proof of his wonderful goodness, through which he governs all things for our salvation. It is therefore our duty, on the other hand, to strive so that the great care which he bestows in saving us may not be in vain.