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1The first book I wrote, Theophilus, concerned all that Jesus began both to do and to teach, 2until the day in which he was received up, after he had given commandment through the Holy Spirit to the apostles whom he had chosen. 3To these he also showed himself alive after his suffering by many proofs, appearing to them over a period of forty days, and spoke about God`s kingdom.
Acts 1:1-3 (WEB)