In the church - The word “church” means literally “the people called out,” and is applied with great propriety to the assembly or multitude called out of Egypt, and separated from the world. It has not, however, of necessity our idea of a church, but means the “assembly,” or people called out of Egypt and placed under the conduct of Moses.
With the angel - In this place there is undoubted reference to the giving of the Law on Mount Sinai. Yet that was done by God himself, Exodus 20: It is clear, therefore, that by “the angel” here, Stephen intends to designate him who was God. It may be observed, however, that “the Law” is represented as having been given by the ministry of an angel (in this place) and by the ministry of “angels,” Acts 7:53; Hebrews 2:2. The essential idea is, that God did it by a messenger, or by mediators. The “character” and “rank” of the messengers, or of the “principal” messenger, must be learned by looking at all the circumstances of the case.
The lively oracles - See Romans 3:2. The word “oracles” here means “commands” or “laws” of God. The word “lively,” or “living” ζῶντα zōnta, stands in opposition to what is dead, or useless, and means what is vigorous, efficacious; and in this place it means that the commands were of such a nature, and given in such circumstances, as to secure attention; to produce obedience; to excite them to act for God - in opposition to laws which would fall powerless, and produce no effect.