Matthew Poole and continuators on Romans 16:18

18. For they that are such, serve not our Lord Jesus Christ, but their own belly ; and by good words and fair speeches deceive the hearts of the simple .

In this verse you have a reason of the foregoing admonition, together with a description of the Seducers, whom they should mark and avoid. He sayes, They are such as serve not the Lord Iesus Christ, but their own belly. i. e. They serve themselves rather than Christ. Though they pretend to be the Servants of Iesus Christ, and give themselves out for his Ministers, yet they aim at nothing but their own commodity and advantage. A further account you have of such persons in Phil. 3.1[illegible: 1 letter]. 1 Tim. 6.5. Tit. 1.11. 2 Pet. 2.3.

q. d. As Satan insinuated into Eve, by pretending he wished her good; so these Seducers pretend they aime at nothing, but the good and benefit of those with whom they have to do: with smooth and flattering words, they praise both the persons and doings of those whom they would ensnare, (so much the word [non-Latin text not transcribed] here used imports) and by this means they impose upon the simple. i. e. The over-credulous and unwary, who do not mistrust any deceit or hurt, the word here rendred (Simple) properly signifies such as are not evil, or that are incautelous and not suspitious.