With them is capable of two principal interpretations: it may refer to all that God had done “for them” (Knox “all God had done to aid them”), but more likely it is to be taken in the sense of what God had done “in union with them” (New English Bible “all that God had done through them”; Zürcher Bibel “all the great things God, who had been with them, had done”; An American Translation* “how God had worked with them”; Barclay “all that God had done along with them”).

The rendering he had opened the way for the Gentiles to believe implies that the expression “to open a door of faith” should be interpreted to mean “to give (someone) the opportunity to believe.” The phrase opened the way for may be equivalent in some languages to “showed how it was possible for” or “showed that the Gentiles could believe.”

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on The Acts of the Apostles. (UBS Handbook Series). New York: UBS, 1972. For this and other handbooks for translators see here .