‘But there was a certain man, Simon by name, who before that time in the city used sorcery, and amazed the people of Samaria, giving out that he himself was some great one, to whom they all gave heed, from the least to the greatest, saying, “This man is that power of God which is called Great.” And they gave heed to him, because that of long time he had amazed them with his sorceries.'
Living among them was a man named Simon who had wooed them with sorcery, and had claimed to be a god-like figure. His powers were such that he had mesmerised the people into following him and calling him ‘the Great One, the Power of God'. In Judaism God was sometimes called ‘the Great One'. But he had clearly been unable to do anything like Philip did. Note that it is repeated twice that he ‘amazed' the people and that they ‘gave heed' to him. His grip was strong. But it was not sufficient to prevent them from turning to the Messiah Whom Philip proclaimed. For here they recognised was a greater power.
‘That power of God which is called Great.' The description may suggest that Luke is quoting his source without fully comprehending what the religious significance of the title was.
Later church history would speak a great deal about a Simon Magus who was a great heretic and was supposed to have founded a Gnostic sect, but there is no certainty that it was this Simon. Simon Magus' name first occurs in the writings of Justin Martyr, who was himself a Samaritan. But Justin does not make any identification with Acts. His name then occurs in Irenaeus, Hippolytus, the Acts of Peter with Simon, and other fictional works. He may well have been a totally different Simon whose life history became intermingled with this ones, for the Simon here in Acts does seem to be portrayed as becoming a genuine, if somewhat mixed up, believer.