John Calvin's Commentary on the Bible

19 (John 13:19)

Verse 19

19.I tell you this now, before it happen. By this statement he reminds his disciples that, when one of their number becomes a reprobate, this is so far from being a good reason for their being discouraged, that it ought to be a more full confirmation of their faith. For if we did not see before our eyes, in the Church, what has been foretold about her distresses and struggles, a doubt might justly arise in our minds, Where are the prophecies? But when the truth of Scripture agrees with our daily experience,17 then do we perceive more clearly, that God takes care of us, and that we are governed by his providence.

That you may believe that I am. (54) By the phrase,that I am, he means that he is that Messiah who had been promised; not that the conduct of Judas, as a traitor, was the first event that led the disciples to the exercise of faith, but because their faith made greater progress, when they arrived at the experience of those things which they had formerly heard from the mouth of Christ. Now this may be explained in two ways; either that Christ says that they will believe after the event has happened, because there was nothing which was hidden from him, or that nothing will be wanting in him of all that the Scripture testifies concerning Christ. As the two interpretations agree well enough together, I leave my readers at liberty to choose which of them they will prefer.

- John Calvin's Commentary on the Bible