John Calvin Commentary 2 Timothy 3:15

"And that from a babe thou hast known the sacred writings which are able to make thee wise unto salvation through faith which is in Christ Jesus." — 2 Timothy 3:15 (ASV)

And that from (thy) childhood This was also no ordinary addition: that he had been accustomed from his infancy to reading the Scripture; for this long habit can make a person much more strongly fortified against every kind of deception. It was therefore a judicious precaution observed in ancient times that those intended for the ministry of the word should be instructed from their infancy in the solid doctrine of godliness, so that when they came to the performance of their office, they might not be inexperienced apprentices. And it should be considered a remarkable instance of God’s kindness, if any person, from his earliest years, has thus acquired a knowledge of the Scriptures.

Which are able to make thee wise unto salvation It is a very high commendation of the Holy Scriptures that we must not seek anywhere else the wisdom which is sufficient for salvation; as the next verse also expresses more fully. But he states, at the same time, what we ought to seek in the Scripture; for false prophets also use it as a pretext. Therefore, in order that it may be useful to us for salvation, it is necessary to understand its right use.

Through faith, which is in Christ Jesus What if someone gives his whole attention to curious questions? What if he adheres to the mere letter of the law and does not seek Christ? What if he perverts the natural meaning by inventions that are foreign to it? For this reason, he directs us to the faith of Christ as the design, and therefore as the sum, of the Scriptures; for on faith depends also what immediately follows.