Jesus gave His followers the instruction to wait until the Holy Spirit had come upon them.
The Holy Spirit experience:
If this was an event which they were just to ‘reckon’ as having happened, there would have been confusion as to how long they should wait!
But Jesus said ‘wait until’ so when the Holy Spirit came they knew that He had filled them, and they experienced His power.
The gift of the Holy Spirit is something that others were aware of. Peter said:
As I began to speak, the Holy Spirit came on them as He had come on us at the beginning.Acts 11:15-17
Then I remembered what the Lord had said,
‘John baptised with water, but you will be baptised with the Holy Spirit.’
So if God gave them the same gift as He gave us, who believed in the Lord Jesus Christ, who was I to think that I could oppose God!”
Peter knew that the gentiles had received the Spirit.
It wasn’t something that they had to ‘reckon’ as just happening.
Here are some other Scriptures which show that receiving the Spirit is something definite :
When Simon saw that the Spirit was given at the laying on of the Apostles hands..”Acts 8:18
God .. has given us the Spirit as a deposit, guaranteeing what is to come.”2 Corinthians 5:5
Having believed, you were marked in Him with a seal, the promised Holy Spirit, who is a deposit guaranteeing our inheritance”Ephesians 1:13-14
When something is given as a guarantee it is a tangible thing, or something known, otherwise it can’t be a guarantee.
Paul looked back at a memorable event for the Galation Christians:
Did you receive the Spirit by observing the Law, or by believing what you heard?”Galations 3:2
The filling of the Holy Spirit is an experience and is felt and is a blessing.
See the next article:  Can we experience the gift of the Holy Spirit?
For the first of these articles see: Looking for revival
[i] Photo credit: The New York Public Library opens in a new window