Grace be, ... - note, Romans 16:20.
That love our Lord Jesus Christ - see the notes on 1 Corinthians 16:22.
In sincerity - Margin, “with incorruption.” With a pure heart; without dissembling; without hypocrisy. There could not be a more appropriate close of the Epistle than such a wish; there will be nothing more needful for us when we come to the close of life than the consciousness that we love the Lord Jesus Christ in sincerity. To writer and reader may this be equally the inestimable consolation then! Better, far better then will be the evidence of such sincere love, than all the wealth which toil can gain, all the honors which the world can bestow - than the most splendid mansion, or the widest fame. The subscription to this Epistle, like those affixed to the other epistles, is of no authority, but in this instance there is every reason to believe that it is correct. Compare notes at the end of the Epistle to the Romans and 1 Corinthians.