There’s no doubt about it. Something awesome, empowering, wonderful, and dramatic is happening here. It was something that even the disciples could not have anticipated exactly as it happened. So it’s easy to understand how the onlooking crowds would have been “utterly amazed.” This is clearly a genuine revival born of the Spirit of God. There was the supernatural wind, the supernatural tongues of fire resting on each of them, and the supernatural ability to speak in real languages that were unlearned by these Galileans. And it all centered in a theme—“declaring the wonders of God.” 16 language groups are mentioned. God was making a profound statement in support of the “Great Commission” (Matthew 28:18-20; Acts 1:8). God clearly intends that the Gospel message be presented in terms understandable by everyone.
Obviously, there was a shift in the venue of the believers from the “upper room” to a place more public, a place where crowds could hear the message presented. There’s no way that hundreds and thousands of people could have clamored into a room upstairs. I observed here a principle of divine design. God has no interest in isolation and exclusivisim. He’s not interested in His people shutting themselves in somewhere to do their own thing—at least not for very long. The last thing Jesus said before returning to Glory was essentially, “You have a message to tell to the nations. Go everywhere "…declaring the wonders of God.”
I think this is a very appropriate question to ask ourselves: “To what degree am I declaring the wonders of God in terms that people can understand?” That’s the language His Spirit would have us speak.