A.T. Robertson Commentary Acts 10:35

"but in every nation he that feareth him, and worketh righteousness, is acceptable to him." — Acts 10:35 (ASV)

Acceptable to him (δεκτος αυτω). Verbal adjective from δεχομα. Acceptabilis. That is to say, a Gentile would not have to become a Jew in order to become a Christian. Evidently Peter had not before perceived this fact. On the great Day of Pentecost when he spoke of the promise "to all those afar off" (2:39) Peter understood that they must first become Jews and then Christians. The new idea that now makes a revolution in Peter's outlook is precisely this that Christ can and will save Gentiles like this Cornelius group without their becoming Jews at all.