You will say, "Who are now under the covenant of works?" There is a vulgar prejudice abroad which supposes that the first covenant was repealed and disannulled upon the fall and that God now deals with us upon new terms, as if the covenant of grace wholly shut out the former contract, wherein they think Adam only was concerned. But this is a gross mistake because it was made not only with Adam but with all his seed. And every natural man, whilst natural, whilst merely a son of Adam, is obliged to the tenor of it. The form of the law runs universally: "Cursed is every one that"…(Gal. 3:10), which rule allows no exception but that of free grace and interest in Christ.
A church is a company of those who are called (and this call must be answered or else it is nothing) to the visible profession of faith in Christ and obedience unto Christ, according to the gospel.