This didn't post to that post so here it is. The elders were of the church as pertains to the narrative in Acts itself.
The Response to Peter’s Address
Acts 2:37 Now when they heard this,[bz] they were acutely distressed[ca] and said to Peter and the rest of the apostles, “What should we do, brothers?” 38 Peter said to them, “Repent, and each one of you be baptized[cb] in the name of Jesus Christ[cc] for[cd] the forgiveness of your sins, and you will receive the gift of the Holy Spirit.[ce] 39 For the promise[cf] is for you and your children, and for all who are far away, as many as the Lord our God will call to himself.” 40 With many other words he testified[cg] and exhorted them saying, “Save yourselves from this perverse[ch] generation!” 41 So those who accepted[ci] his message[cj] were baptized, and that day about 3,000 people[ck] were added.[cl]
The Response to Peter’s Address
Acts 2:37 Now when they heard this,[bz] they were acutely distressed[ca] and said to Peter and the rest of the apostles, “What should we do, brothers?” 38 Peter said to them, “Repent, and each one of you be baptized[cb] in the name of Jesus Christ[cc] for[cd] the forgiveness of your sins, and you will receive the gift of the Holy Spirit.[ce] 39 For the promise[cf] is for you and your children, and for all who are far away, as many as the Lord our God will call to himself.” 40 With many other words he testified[cg] and exhorted them saying, “Save yourselves from this perverse[ch] generation!” 41 So those who accepted[ci] his message[cj] were baptized, and that day about 3,000 people[ck] were added.[cl]
Πέτρος δὲ πρὸς αὐτούς Μετανοήσατε, καὶ βαπτισθήτω ἕκαστος ὑμῶν ἐπὶ τῷ ὀνόματι Ἰησοῦ Χριστοῦ εἰς ἄφεσιν τῶν ἁμαρτιῶν ὑμῶν, καὶ λήμψεσθε τὴν δωρεὰν τοῦ Ἁγίου Πνεύματος.
if: baptistheto=be immersed; epi=on; onomati=authority; eis=into
You end up with this:
Peter then to them, repent, and be immersed, every one of you, on the authority of Jesus Christ into forgiveness of the sins of you, and you will receive the gift of the Holy Spirit.
In this case it is not be baptized in water to receive forgiveness of sins. It becomes be immersed into forgiveness of sins upon repentance, and it them matches Luke 24:47 exactly.
Here is Luke 24:47
καὶ κηρυχθῆναι ἐπὶ τῷ ὀνόματι αὐτοῦ μετάνοιαν εἰς ἄφεσιν ἁμαρτιῶν εἰς πάντα τὰ ἔθνη, — ἀρξάμενοι ἀπὸ Ἱερουσαλήμ.
and to be proclaimed on the authority of him repentance into forgiveness of sins to all nations, having begun from Jerusalem.