Consider the following passages:
“But when the Helper comes, whom I shall send to you from the Father, the Spirit of truth who proceeds from the Father, He will testify of Me.” (John 15:26)
Nevertheless I tell you the truth. It is to your advantage that I go away; for if I do not go away, the Helper will not come to you; but if I depart, I will send Him to you.” (John 16:7)
And being assembled together with them, He commanded them not to depart from Jerusalem, but to wait for the Promise of the Father, “which,” He said, “you have heard from Me; for John truly baptized with water, but you shall be baptized with the Holy Spirit not many days from now.” (Acts 1:4-5)
“This Jesus God has raised up, of which we are all witnesses. Therefore being exalted to the right hand of God, and having received from the Father the promise of the Holy Spirit, He poured out this which you now see and hear.” (Acts 2:32-33)
In each of these passages we see that Jesus did indeed keep His promise to send the Holy Spirit to help His followers. This helping came by way of the Spirit indwelling those followers. The dawn of this new era was the Day of Pentecost that is described in Acts chapter 2, but the era continues today as each person who believes in Christ as Savior is “baptized” with (indwelt by) the Holy Spirit from the moment of the belief. As Romans 8:9 puts it:
…Now if anyone does not have the Spirit of Christ, he is not His.
But what does the coming of the Holy Spirit to indwell believers have to do with Easter? That’s simple. The fact that the Holy Spirit came proves that Jesus did rise from the dead. Think about it, He had to resurrect and ascend before He could send. So to deny Christ’s resurrection is to deny some 2,000 years worth of the Holy Spirit ministering through Christians. That’s a lot of denial, much more than is logical in light of all the good Christians have done down through the centuries.