Acts of the Apostles 2:41-42, 47

Those who believed what Peter said were baptized and added to the church that day—about 3,000 in all. All the believers devoted themselves to the apostles’ teaching, and to fellowship, and to sharing in meals (including the Lord’s Supper), and to prayer.

all the while praising God and enjoying the goodwill of all the people. And each day the Lord added to their fellowship those who were being saved.