Romans 16:18

For they that are such serve not our Lord Jesus Christ,.... They do not preach him, but themselves; they do not seek the things of Christ, his honour and glory, the spread of his Gospel, and the enlargement of his kingdom and interest; they seek their own things, worldly honour and applause, riches, wealth, and grandeur; they seek to please men, and so are not the servants of Christ: they introduced the observance of meats and drinks in to the kingdom of Christ, which it do not consist of, and neglected the doctrines of righteousness and peace, from whence springs joy in the Holy Ghost, and so in these spiritual things did not serve Christ; and therefore, as they were not acceptable to God, were not to be approved of by Christian men, but to be marked and avoided:

but their own belly; which they made a god of, and devoted themselves to the service of all their views were to gratify and indulge their sensual appetite. The false teachers among the Jews were particularly addicted to this vice: hence the apostle sometimes calls them dogs, Philippians 3:2, on account of their voraciousness, and who, in Isaiah's time, were greedy ones that could never have enough,

Isaiah 56:11; and in our Lord's time devoured widows' houses, under a pretence of long prayers for them, Matthew 23:14; and were like the Cretians, evil beasts, and slow bellies, Titus 1:12, unwilling to labour, and lived upon the spoil of others:

and by good words, and fair speeches, deceive the hearts of the simple: they were deceivers; they lay in wait to deceive, made use of the hidden things of dishonesty, walked in craftiness, and handled the word of God deceitfully; and therefore to be marked and avoided: they deceived "the simple", harmless, and innocent, that think no evil, nor are aware of any; who have little understanding of things; persons of weak minds, easy to be imposed upon; very credulous, ready to believe every word, so the simple man does, as Solomon says, Proverbs 14:15; and such false teachers choose to tamper with, and make their attacks upon, being able to gain upon them the most easily, as their father the devil, the old serpent, did, when he first assailed human nature: the "hearts" of these they deceive; they work upon their affections, blind their understandings, impose on their judgments, and corrupt their minds from the simplicity that is in Christ: and this they do "by good words and fair speeches"; either by making use of the words of Scripture, and a show of arguments taken from thence; so Satan cited Scripture in his dispute with our Lord; and so heretics, in all ages, have pretended toil in favour of their principles, by which means they have gained on many to follow their pernicious ways; or by using words and phrases that faithful ministers of Christ use, such as the grace of God, the righteousness of Christ, the Spirit of Christ, but in a different sense; as some among us now frequently make mention of them, when they mean no more by them than the light of nature within them, and the dictates of a natural conscience; or by an elegant style, a set of fine words, a flow of rhetorical expressions, great swelling words of vanity, which such men generally affect, and so work themselves into the admiration of the common people; or by doctrines suited to the carnal minds and reasonings of men, which tickle human nature, and swell it with pride and vanity; as by preaching up the purity and power of it, asserting man's free will, and the strength of it to that which is good; the capacity of man to keep the law, and perform good works; justification by them before God, and acceptance with him, on account of them; atonement for sins committed, by repentance and reformation; that God does not regard trifling things, some sins are venial, and easily passed over; that concupiscence is no sin; God does not rigorously exact duty, he takes the will for the deed, and is merciful unto all, and if but sincere, there is no doubt of heaven; and such men, generally speaking, instead of correcting vice, and reproving men for their sins, connive at them, indulge them in them, soothe and flatter, commend and defend them, whereby they attach them to their persons and interest.