John Calvin Commentary Acts 1:16

"Brethren, it was needful that the Scripture should be fulfilled, which the Holy Spirit spake before by the mouth of David concerning Judas, who was guide to them that took Jesus." — Acts 1:16 (ASV)

It was fitting that the Scripture should be fulfilled. Because Peter speaks in this, their assembly, therefore the Papists maintain he is the head of the church. As though no one could speak in any assembly of the godly without immediately becoming Pope.

We grant that, as in every assembly there must be some who are chief, so in this assembly the apostles ascribed this honor to Peter. But how does this prove their Papacy? Therefore, setting that argument aside, let us consider what the Spirit speaks by the mouth of Peter.

He says that the Scripture necessarily had to be fulfilled, so that no one's mind would be troubled by that horrible fall of Judas. For it seemed a strange thing that he who was chosen by Christ to such an excellent office should fall so disgracefully in the beginning of his course.

Peter removes this stone of stumbling when he says that it was foretold by Scripture. From this we may gather a very necessary admonition for daily practice: namely, that we ought to attribute this honor to the prophecies of the Scriptures, that they are able to calm all such fear as we feel at unexpected events.

For there is nothing that troubles us more than when we rely on our own sense and understanding, and so bring upon ourselves hindrances and doubts. The Lord would be ready to cure these if only we would hold fast to this one thing: that nothing is absurd which He has foreseen, appointed, and foretold, so that He might make us stronger.

Judas was not, therefore, excusable because what happened to him was foretold, since he fell away, not compelled by the prophecy, but only by the malice of his own heart.

Peter's oration has two parts:

1. First, he removes the offense that godly minds might have taken because of Judas's fall, from which he also draws an exhortation so that the others may learn to fear God.
2. Secondly, he tells them that it remains for them to choose another in his place, both of which he proves by the testimony of Scripture.

Which the Holy Ghost foretold. Speeches of this kind bring greater reverence to the Scriptures, while we are taught by them that David and all the rest of the prophets spoke only as they were directed by the Holy Ghost, so that they themselves were not the authors of their prophecies, but the Spirit who used their tongues as an instrument. Therefore, since our dullness is so great that we ascribe less authority to the Scriptures than we should, we must diligently note such ways of speaking and become familiar with them, so that we may frequently remember God's authority and thereby confirm our faith.