37Now when they heard this, they were pierced to the heart, and said to Peter and the rest of the apostles, “Brethren, what shall we do?” 38Peter said to them, “Repent, and each of you be baptized in the name of Jesus Christ for the forgiveness of your sins; and you will receive the gift of the Holy Spirit. 39“For the promise is for you and your children and for all who are far off, as many as the Lord our God will call to Himself.” 40And with many other words he solemnly testified and kept on exhorting them, saying, “Be saved from this perverse generation!” 41So then, those who had received his word were baptized; and that day there were added about three thousand souls. Acts 2:37-41 NASB
Yes, but that was not typical “church”. Virtually everyone warming pews in all of the churches I’ve been to are already professing to be Christian. However, when there is an outreach (like the youth camp type of stuff), this is much more appropriate.
i.e. the event in Acts 2 was not a “church service”. It would have more in common with the modern “tent revival”. That is, the majority of people there have never really heard the message. That is not what a weekly meeting of believers is.