ISB ~ Acts 1 v3

many proofs:The Resurrection of Jesus is a miracle substantiated by multiple strands of historical evidence (CCC 640-44). (1) His tomb was empty Easter morning (Jn 20:4-9); (2) he presented himself alive to the apostles and other disciples that evening (Lk 24:13-31; Jn 20:19-20); (3) he invited eyewitnesses to touch his risen body and examine his wounds (Lk 24:36-43; Jn 20:26-29); (4) he showed himself risen to more than 500 people (1 Cor 15:6); and (5) his appearance to the Church’s fiercest adversary, Saul of Tarsus, transformed him into her most zealous apostle (9:1-19).

forty days:A period of final instruction between Easter Sunday and Ascension Thursday. The number 40 signifies a time of preparation for the disciples, just as Jesus underwent 40 days of preparation before his own ministry (Mt 4:2). For other symbolic meanings of the number 40, See note on Lk 4:2.

the kingdom of God:A central pillar in the apostolic preaching of Acts (8:12; 14:22; 19:8; 20:25; 28:23, 31).