John Chrysostom

For since he said, God beseeches, and we are ambassadors and suppliants unto you, that ye be "reconciled unto God:" lest they should become supine, he hereby again alarms and arouses them, saying: "We intreat that ye receive not the grace of God in vain." 'For let us not,' he says, 'therefore be at ease, because He beseeches and hath sent some to be ambassadors; nay, but for this very reason let us make haste to please God and to collect spiritual merchandise;' as also he said above, "The love of God constraineth us," (ch. v. 14) that is presseth, driveth, urgeth us, 'that ye may not after so much affectionate care, by being supine and exhibiting no nobleness, miss of such great blessings. Do not therefore because He hath sent some to exhort you, deem that this will always be so. It will be so until His second coming; until then He beseeches, so long as we are here; but after that is judgment and punishment.' Therefore, he says, "we are constrained."

For lest they should think that this of itself is "reconciliation," believing on Him that calleth; he adds these words, requiting that earnestness which respects the life. For, for one who hath been freed from sins and made a friend to wallow in the former things, is to return again unto enmity, and to "receive the grace in vain," in respect of the life. For from "the grace" we reap no benefit towards salvation, if we live impurely; nay, we are even harmed, having this greater aggravation even of our sins, in that after such knowledge and such a gift we have gone back to our former vices. This however he does not mention as yet: that he may not make his work harsh, but says only that we reap no benefit.