Saving faith is a gift from God. Faith in spirits, idols, and false gods is not. Faith from God can be recognized by 1) its object—God, 2) its unwavering quality, and 3) its saving results. God causes this kind of faith in a particular way: "Consequently, faith comes from hearing the message, and the message is heard through the word of Christ" (Romans 10:17).
Faith is caused by hearing the Word preached. It should not surprise us when someone says, “Don’t use the Bible,” or, “Don’t preach to me, I don’t believe that stuff.” Of course he does not believe—he hasn’t heard it.
"For there is no difference between Jew and Gentile—the same Lord is Lord of all and richly blesses all who call on him, for, 'Everyone who calls on the name of the Lord will be saved.' How, then, can they call on the one they have not believed in? And how can they believe in the one of whom they have not heard? And how can they hear without someone preaching to them? And how can they preach unless they are sent? As it is written, 'How beautiful are the feet of those who bring good news!'” (Romans 10:12-15).
The miracle in Acts 2:1-13 did not get saving results. It got an audience. It was the preaching in Acts 2:22-41 that resulted in three thousand converts. The same thing happened with the miracles and preaching in Acts 3 and Acts 14.