John 17:20

20.And I ask not for these only. He now gives a wider range to his prayer, which hitherto had included the apostles alone; for he extends it to all the disciples of the Gospel, so long as there shall be any of them to the end of the world. This is assuredly a remarkable ground of confidence; for if we believe in Christ through the doctrine of the Gospel, we ought to entertain no doubt that we are already gathered with the apostles into his faithful protection, so that not one of us shall perish. This prayer of Christ is a safe harbour, and whoever retreats into it is safe from all danger of shipwreck; for it is as if Christ had solemnly sworn that he will devote his care and diligence to our salvation.

He began with his apostles, that their salvation, which we know to be certain, might make us more certain of our own salvation; and, therefore, whenever Satan attacks us, let us learn to meet him with this shield, that it is not to no purpose that the Son of God united us with the apostles, so that the salvation of all was bound up, as it were, in the same bundle. There is nothing, therefore that ought more powerfully to excite us to embrace the Gospel; for as it is an inestimable blessing that we are presented to God by the hand of Chrisb to be preserved from destruction, so we ought justly to love it, and to care for it above all things else. In this respect the madness of the world is monstrous. All desire salvation; Christ instructs us in a way of obtaining it, from which if any one turn aside, there remains for him no good hope; and yet scarcely one person in a hundred deigns to receive what was so graciously offered.

For those who shall believe on me, We must attend to this form of expression. Christ prays for all who shall believe in him. By these words he reminds us of what we have sometimes said already, that our faith ought to be directed to him. The clause which immediately follows, through their word, expresses admirably the power and nature of faith, and at the same time is a familiar confirmation to us who know that our faith is founded on the Gospel taught by the apostles. Let the world then condemn us a thousand times, this alone ought to satisfy us, that Christ acknowledges us to be his heritage and pleads with the Father for us.

But woe to the Papists, whose faith is so far removed from this rule, that they are not ashamed to vomit out this horrid blasphemy, that there is nothing in Scripture but what is ambiguous, and may be turned in a variety of ways. The tradition of the Church is therefore their only authoritative guide to what they shall believe. But let us remember that the Son of God, who alone is competent to judge, does not approve of any other faith (123) than that which is drawn from the doctrine of the apostles, and sure information of that doctrine will be found no where else than in their writings.

We must also observe that form of expression, to believe through the word, which means that faith springs from hearing, because the outward preaching of men is the instrument by which God draws us to faith. It follows, that God is, strictly speaking, the Author of faith, and men are the ministers by whom we believe, as Paul teaches (1 Corinthians 3:5.)