>>They saw tongues like flames of a fire that separated and came to rest on each of them.
>>And they were all filled with the Holy Spirit ...
....for the very first time. Not just for each them personally, but this was the start of the human race being filled with the Holy Spirit. 2000 years later, we still have the Holy Spirit living in us. A revival does not send tongues of flame down because it is already there. All revivals do is prime us to listen to the voice we already hear and ignore. A month later, most are back to their old ways and blaming it on the idea that the Holy Spirit has left them.
“... this was the start of the human race being filled with the Holy Spirit.” Shouldn’t we differentiate such that those who believe in Whom God has sent for us and our salvation have the Holy Spirit in them?