John Calvin Commentary 2 Timothy 1:5

"having been reminded of the unfeigned faith that is in thee; which dwelt first in thy grandmother Lois, and thy mother Eunice; and, I am persuaded, in thee also." — 2 Timothy 1:5 (ASV)

Calling to remembrance that unfeigned faith: not so much to applaud Timothy as to exhort him, the Apostle commends both Timothy's own faith and that of his grandmother and mother. For when someone has begun well and valiantly, the progress they have made should encourage them to continue, and family examples are powerful incentives to urge them forward. Accordingly, Paul sets before him his grandmother Lois and his mother Eunice, by whom he had been educated from his infancy in such a way that he might have absorbed godliness along with his mother's milk. Therefore, by this godly education, Timothy is admonished not to become unworthy of himself or his ancestors.

It is uncertain whether, on the one hand, these women were converted to Christ and what Paul applauds here was the beginning of their faith, or whether, on the other hand, faith is attributed to them apart from Christianity. The latter seems more probable to me. For, although at that time everything abounded with many superstitions and corruptions, yet God always had His own people. He did not allow them to be corrupted by the crowd, but He sanctified and separated them to Himself, so that there might always exist among the Jews a pledge of this grace, which He had promised to the seed of Abraham. Therefore, there is no absurdity in saying that they lived and died in the faith of the Mediator, even though Christ had not yet been revealed to them. But I do not assert anything, and could not do so without rashness.

And I am persuaded that in you also: this clause confirms me in the conjecture I have just stated. For, in my opinion, Paul is not speaking here of Timothy's present faith. It would lessen the sure confidence of the previous praise if Paul only said that he considered Timothy's faith to resemble that of his grandmother and mother. But I understand the meaning to be that Timothy, from his childhood, even before he had gained a knowledge of the gospel, was filled with the fear of God and with such faith as proved to be a living seed, which later revealed itself.