Acts 2:37-41 - The Response To Peter's Sermon
37 Now when the people heard this message [of Peter and the other apostles, See verse 14], they were convicted [of its truth] in their hearts and said to Peter and the other apostles, "Brothers, what shall we do [about our condemned condition]?"
38 And Peter replied, "Every one of you must repent [i.e., change your hearts and lives] and be immersed in the name of Jesus Christ [i.e., by His authority] so that your sins will be forgiven [by God] and then you will receive the gift of the Holy Spirit [to live in your hearts]. 39 For the promise [of forgiveness and the Holy Spirit] is being given to you [Jews] and to your descendants and [also] to all those who are far away [i.e., Gentiles. See Eph. 2:17]. [This promise is] to as many as [respond to] the Lord, our God's call [through the Gospel, See II Thess. 2:14]." 40 So, Peter testified and urged the crowd with many additional words, saying, "Save yourselves from [the condemnation coming on] this sinful generation [by responding to this message]."
41 Then those who responded [by faith] to the words [spoken by Peter and the apostles] were immersed, and about three thousand persons were added to them [i.e., the apostles] on that day.