Acts 15:4

παρεδέχθησαν ὑπὸ τῆς ἐκκλησίας, they were received by the Church. The ἐκκλησία is perhaps named first because there would on such a visit be an assembly of the whole Christian body to hear the story of the missionary labours of Paul and Barnabas before the question about which they had specially been sent from Antioch came to be discussed. The account of the spreading of the faith was for all, while the question of circumcision would be discussed only by the heads of the Church, and those who could speak with authority. This preliminary meeting must have lasted for a considerable time, even if only a mere abstract of the labours, sufferings and success of Paul and Barnabas were given to those who met them. Such a recital was the best introduction that could be conceived for the question which was afterwards to be discussed and legislated on.

μετ' αὐτῶν, with them. On this preposition cf. Acts 14:27. That the Apostles had a true notion of themselves as only instruments, though Christ deigned to be a fellow-worker (Mark 16:20) with them, is seen below in Acts 15:12 where the preposition used is διὰ (by).