There is some debate as to whether or not Simon was a genuine believer. In favour is the fact that he is said to have believed in the good news of the kingdom of God and that he was baptized.1 Exactly that which happened to other believers from Samaria happened with Simon.
In opposition to this is the fact that his heart's commitment was a desire to magnify himself (Acts 8:21).2 The content of his faith was also left open (it is not said specifically what he believed), and he seemed to have been fascinated more by Philip’s signs and wonders than by the message of the gospel.3
From what Luke tells us, we must most probably conclude that Simon did believe, although he displayed significant weaknesses in his faith.
13 Even Simon himself believed, and after being baptized he continued with Philip. And seeing signs and great miracles performed, he was amazed.