2 Timothy 3:14

14But as for thee, continue in those things which thou hast learned Although wickedness prevail, and push its way forward, he advises Timothy nevertheless to stand firm. And undoubtedly this is the actual trial of faith, when we offer unwearied resistance to all the contrivances of Satan, and do not alter our course for every wind that blows, but remain steadfast on the truth of God, as on a sure anchor.

Knowing from whom thou hast learned them This is said for the purpose of commending the certainty of the doctrine; for, if any one has been wrong instructed, he ought not to persevere in it. On the contrary, we ought to unlearn all that we have learned apart from Christ, if we wish to be his disciples; as, for example, it is the commencement of our pure instruction in the faith to reject and forget all the instruction of Popery. The Apostle therefore does not enjoin Timothy to defend indiscriminately the doctrine which has been delivered to him, but only that which he knows to be truth; by which he means, that he must make a selection. (190) Besides, he does not claim this as a private individual, that what he has taught shall be reckoned to be a divine revelation; but he boldly asserts his own authority to Timothy, who, he was aware, knew that his fidelity and his calling had been proved. And if he was fully convinced that he had been taught by an Apostle of Christ, he concluded that therefore it was not a doctrine of man, but of Christ.

This passage teaches us, that we ought to be as careful to guard against obstinacy in matters that are uncertain, (such as all the doctrines of men are,) as to hold within unshaken firmness the truth of God. Besides, we learn from it, that faith ought to be accompanied by prudence, that it may distinguish between the word of God and the word of men, so that we may not adopt at random everything that is brought forward. Nothing is more inconsistent with the nature of faith than light credulity, which allows us to embrace everything indiscriminately, whatever it may be, and from whomsoever it proceeds; because it is the chief foundation of faith, to know that it has God for its author.

And which have been intrusted to thee (191) When he adds, that the doctrine had been intrusted to Timothy, this gives ( αὔξησιν) additional force to the exhortation; for to “commit a thing in trust” is something more than merely to deliver it. Now Timothy had not been taught as one of the common people, but in order that he might faithfully deliver into the hands of others what he had received.