Acts 2:41

Acts 2:41. Then they that gladly received his word were baptized: and the same day there were added to them about three thousand souls. Several commentators remark here, that as during the course at least of that day three thousand persons received baptism, this great multitude could not have been immersed, especially in a city like Jerusalem, where the supply of water was not abundant. This first baptism probably was administered by sprinkling or pouring. It is noteworthy that on this occasion ‘the baptized' could have received little or no instruction in the faith. In this case instruction must have followed baptism. Olshausen, quoted by Gloag, remarks, ‘We may see it was not dogmas (as a preparation for baptism) upon which the apostles laid stress, but the disposition and bent of the mind.'