16:17-20 How earnest, how endearing are these exhortations! Whatever differs from the sound doctrine of the Scriptures, opens a door to divisions and offences. If truth be forsaken, unity and peace will not last long. Many call Christ, Master and Lord, who are far from serving him. But they serve their carnal, sensual, worldly interests. They corrupt the head by deceiving the heart; perverting the judgments by winding themselves into the affections. We have great need to keep our hearts with all diligence. It has been the common policy of seducers to set upon those who are softened by convictions. A pliable temper is good when under good guidance, otherwise it may be easily led astray. Be so wise as not to be deceived, yet so simple as not to be deceivers. The blessing the apostle expects from God, is victory over Satan. This includes all designs and devices of Satan against souls, to defile, disturb, and destroy them; all his attempts to keep us from the peace of heaven here, and the possession of heaven hereafter. When Satan seems to prevail, and we are ready to give up all as lost, then will the God of peace interpose in our behalf. Hold out therefore, faith and patience, yet a little while. If the grace of Christ be with us, who can prevail against us?

18. For they that are such serve not our Lord Jesus Christ—"our Lord Christ" appears to be the true reading.

but their own belly—not in the grosset sense, but as "living for low ends of their own" (compare Php 3:19).

and by good words and fair speeches deceive the simple—the unwary, the unsuspecting. (See Pr 14:15).