The next reference to “repentance” in Acts is found in in Paul’s sermon to the Jewish synagogue at Antioch in Pisidia. Paul, in identifying Jesus, associates him with John the Baptist, who had first preached “repentance” to Israel to prepare the way:
22 When he had removed him, he raised up David to be their king, to whom he also testified, ‘I have found David the son of Jesse, a man after my heart, who will do all my will.’ 23 From this man’s offspring, God has brought salvation to Israel according to his promise, 24 before his coming, when John had first preached the baptism of repentance (metanoias) to Israel. 25 As John was fulfilling his course, he said, ‘What do you suppose that I am? I am not he. But behold, one comes after me the sandals of whose feet I am not worthy to untie.’ 26 Brothers, children of the stock of Abraham, and those among you who fear God, the word of this salvation is sent out to you.
While Acts 13 nowhere specifies that the “repentance” here referenced involves any change in behavior, other than by using the stronger word, metanoia, the fact that the reference is made as part of the description of the preaching of John implies this. In Matthew 3:1-12, and in Luke 3:1-14, the message of John the Baptist is clearly one of “repentance” from our mistreatment of each other, and “repentance” to behavioral fruits worthy of repentance, as has previously been shown (see Repentance, Changed Way of Life, and John’s Baptism). Paul’s Jewish audience in the Antioch synagogue would have been familiar with this.