And we are his witnesses - For this purpose they had been appointed, Acts 1:8, Acts 1:21-22; Acts 2:32; Acts 3:15; Luke 24:48.
Of these things - Particularly of the resurrection of the Lord Jesus, and of the events which had followed it. Perhaps, however, he meant to include everything pertaining to the life, teachings, and death of the Lord Jesus.
And so is also ... - The descent of the Holy Spirit to endow them with remarkable gifts Acts 2:1-4, to awaken and convert such a multitude Acts 2:41; Acts 4:4; Acts 5:14, was an unanswerable attestation of the truth of these doctrines and of the Christian religion. So manifest and decided was the presence of God attending them, that “they” could have no doubt that what they said was true; and so open and public was this attestation, that it was an evidence to all the people of the truth of their doctrine.