Now the end of the commandment is charity out of a pure heart, and of a good conscience, and of faith unfeigned:
Now - Greek, 'But,' in contrast to the unedifying doctrine (1 Timothy 1:3-4).
The end - the aim.
The commandment, х parangelias (G3852)] - 'of the charge:' the same "charge" as 1 Timothy 1:3; 1 Timothy 1:18; here including the gospel 'dispensation of God' (note, 1 Timothy 1:4; 1 Timothy 1:11), the sum and substance of the "charge" (the practical, preceptive teaching) committed to Timothy wherewith to "charge" his flock.
Charity - LOVE: the sum and end of the law and Gospel alike; that wherein the Gospel fulfils the spirit of the law in its every essential tittle (Romans 13:10). The foundation is faith (1 Timothy 1:4), the "end" is love (1 Timothy 1:14; Titus 3:15); whereas the 'questions gender strife' (2 Timothy 2:23).
Out of - springing as from a fountain.
Pure heart - purified by faith (Luke 10:27; Acts 15:9; 2 Timothy 2:22; 1 Peter 1:22). The heart, the center of the feelings and the imaginations of the soul.
Good conscience - cleared from guilt by sound faith in Christ (Acts 23:1; Acts 5:19; 1 Timothy 3:9; 2 Timothy 1:3; 1 Peter 3:16; 1 Peter 3:21; Hebrews 13:18). John uses "heart" where Paul uses "conscience." In Paul the understanding is the seat of conscience, the heart of love (Bengel). A good conscience is joined with sound faith; a bad conscience, with unsound faith (cf. Hebrews 9:9; Hebrews 9:14). Conscience is threefold-an exponent of moral law, a judge, and a sentiment (McCosh in 'Ellicott').
Faith unfeigned - not hypocritical and unfruitful, but working by love (Galatians 5:6). So "unfeigned" is said of "love," Romans 12:9; brotherly love, 1 Peter 1:21; the wisdom from above, James 3:17. Faith is feigned where there is not "good conscience." The false teachers drew men off from a loving, working, real faith, to profitless, speculative "questions" (1 Timothy 1:4): they were just the opposite, "of corrupt minds," 1 Timothy 6:5; "conscience seared," 1 Timothy 4:2; Titus 1:15, "unbelieving;" "reprobate concerning the faith," 2 Timothy 3:8: cf. Hebrews 3:12.