Actually, there's more than one way to demonstrate that the Holy Spirit is God, or as theologians say, to demonstrate the divinity of the Holy Spirit. First of all, we see the divinity of the Holy Spirit in creation, his role in creation. In Genesis chapter 1 verses 1 and 2:

"In the beginning, God created the heavens and the earth. The earth was without form and void, and darkness was over the face of the deep. And the Spirit of God was hovering over the face of the waters."

There are two things here: First, the Scripture does not tell us that God created the Holy Spirit. He is not created. He is the Creator. He is God. This is the first thing. The second thing is that the Holy Spirit of God participated in the process of creation—not just that he is not created, but also he participated in the process of creation because he is God, and therefore he is the Creator. In the expression, "And the Spirit of God was hovering over the face of the waters," we see here the image of a bird who hovers over the nest of his chicks. It's like he's embracing his nest and is giving life. So, the image here is that the Spirit of God is the one who gives life to the world. He is the Creator, and therefore we see here the divinity of the Holy Spirit.

Also there's a second way that shows us his divinity—his role in the revelation. He reveals himself through the Son and also through the Holy Spirit. I would like to read from 1 Corinthians chapter 2 verses 9, 10, and 11:

But, as it is written, "What no eye has seen, nor ear heard, nor the heart of man imagined, what God has prepared for those who love him‐these things God has revealed to us through the Spirit. For the Spirit searches everything, even the depths of God. For who knows a person's thoughts except the spirit of that person, which is in him? So also no one comprehends the thoughts of God except the Spirit of God."

The words here are clear. In order for the Holy Spirit to reveal God, he has to be equal to God; he has to know God's thoughts. It's impossible for an angel or any creature to reveal the Creator because he cannot search the depths of God. But as the spirit of man knows all of man's depths, the Spirit of God knows everything in God's depths, and this demonstrates to us the divinity of the Holy Spirit.

Also, we can demonstrate the divinity of the Holy Spirit through his role in the general resurrection. He is going to have a role in the resurrection of our bodies. And this is what we read about in Romans chapter 8 verse 11:

"If the Spirit of him who raised Jesus from the dead dwells in you, he—the Father by the way—who raised Christ Jesus from the dead will also give life to your mortal bodies through his Spirit who dwells in you."

So, God the Father will raise our bodies in the resurrection day through his Spirit who dwells in us. If the Spirit of God is not God, how will he be able to raise the dead?