Where does it say in the scriptures that at the moment we believe we will receive the Holy Spirit? None of the passages that you have brought up on your radio show actually says that. By what you have said then there were no believers before Pentecost.
There were believers before Pentecost and Adam & Eve were the first believers. Prior to Pentecost believers were not Permanently indwelt as they are during this age. Galatians 3:3 asks the question of the Galatians, “Received you the Spirit by the works of the law, or by the hearing of faith? The implied answer is that when they trusted Christ they received the Spirit of God.