The Gentiles, and especially the Greeks, were extremely licentious, and there was danger that some, unconverted in heart, would make a profession of faith without renouncing their evil practices. The Jewish Christians could not tolerate the immorality that was not even regarded as criminal by the heathen. The Jews therefore held it as highly proper that circumcision and the observance of the ceremonial law should be enjoined on the Gentile converts as a test of their sincerity and devotion. This, they believed, would prevent the addition to the church of those who, adopting the faith without true conversion of heart, might afterward bring reproach upon the cause by immorality and excess.

Hedningerne og i særdeleshed grækerne var overordentlig løsslupne i deres livsførelse, og der var fare for, at nogle af dem, der ikke i deres inderste var blevet omvendt, skulle foregive at være kristne uden at ville give afkald på deres slette vaner. De jødekristne ville ikke finde sig i den umoralitet, som hedningerne end ikke regnede for noget syndigt. Derfor betragtede jøderne det som i høj grad betimeligt, at omskærelse og overholdelse af loven om ceremonier skulle pålægges de hedningekristne som bevis på deres oprigtighed og gudsfrygt. De mente, at dette ville befri kirken for tilgang af dem, der ved at antage troen uden virkelig af hjertet at have omvendt sig, senere kunne komme til at bringe sagen i vanry ved umoralitet og udskejelser.