2 Timothy 1:5

When I call to remembrance--This increased his "desire to see" Timothy. The oldest manuscripts read, "When I called to remembrance"; implying that some recent incident (perhaps the contrasted cowardice of the hypocrite Demas, who forsook him) had reminded him of the sincerity of Timothy's faith. faith that is in thee--ALFORD translates, "that was in thee." He remembers Timothy's faith in the past as a fact; its present existence in him is only matter of his confident persuasion or hope. which--Greek, "such as." dwelt--"made its dwelling" or abode (Joh 14:23). The past tense implies they were now dead. first--before it dwelt in thee. She was the furthest back of the progenitors of Timothy whom Paul knew. mother Eunice--a believing Jewess; but his father was a Greek, that is, a heathen (Act 16:1). The faith of the one parent sanctified the child (Ti2 3:15; Co1 7:14). She was probably converted at Paul's first visit to Lystra (Act 14:6). It is an undesigned coincidence, and so a mark of truth, that in Act 16:1 the belief of the mother alone is mentioned, just as here praise is bestowed on the faith of the mother, while no notice is taken of the father [PALEY, HorÃ&brvbr PaulinÃ&brvbr]. and--Greek, "but," that is, notwithstanding appearances [ALFORD]. persuaded that--it dwells, or it shall dwell "in thee also." The mention of the faith of his mother and grandmother is designed as an incentive to stir up his faith.

— Jamieson-Fausset-Brown Commentary (public domain)