The day of Pentecost frees the apostles to believe in a God who is actively involved in their lives and no longer a mere intellectual belief. The Holy Spirit has become wind, fire, joy, excitement, universal shareability, and not just another boring Sabbath obligation or more commandments to obey. Notice how all the metaphors of Spirit presence are dynamic, alive, moving, and universal.
The Spirit will always be totally unmerited grace. She always takes the initiative. The Holy Spirit is experienced as intimacy and warmth and fire, as the power to love beyond boundaries and ethnicities. She is presented as surprising, elusive and free, and yet totally given. The Spirit comes from no place we can control, least of all by our good behavior or even our bad behavior. All we can do is surrender and enjoy.