1. He is the third person of the trinity. He is not a wind or fire or dove.
He is the Spirit of God: He came upon those of the old testament but lives in us believers.
When he and his servant arrived at Gibeah, a procession of prophets met him; the Spirit of God came powerfully upon him, and he joined in their prophesying. *1Sam 10:10*
The Spirit lifted me up and brought me to the exiles in Babylonia in the vision given by the Spirit of God... *Ezekiel 11:24*
For all who are led by the Spirit of God are children of God. *Romans 8:14*
The Spirit of God, who raised Jesus from the dead, lives in you. And just as God raised Christ Jesus from the dead, he will give life to your mortal bodies by this same Spirit living within you. *Romans 8:11*
2. He is God's gift to all believers: He makes his abode in us.
On one occasion, while he was eating with them, he gave them this command: "Do not leave Jerusalem, but wait for the gift my Father promised, which you have heard me speak about. For John baptized with water, but in a few days you will be baptized with the Holy Spirit. *Act 1:4-5*
If you then, though you are evil, know how to give good gifts to your children, how much more will your Father in heaven give the Holy Spirit to those who ask him! *Matthew 7:11*
The circumcised believers who had come with Peter were astonished that the gift of the Holy Spirit had been poured out even on Gentiles. *Acts 10:45*
Peter replied, "Each of you must repent of your sins and turn to God, and be baptized in the name of Jesus Christ for the forgiveness of your sins. Then you will receive the gift of the Holy Spirit. *Acts 2:38*
3. He is our counselor, guide and revealer of truths/secrets: We have access to the mind and plans of God because of the Holy Spirit.
But we know these things because God has revealed them to us by his Spirit, and his Spirit searches out everything and shows us even God's deep secrets. No one can know what anyone else is really thinking except that person alone and no one can know God's thoughts except God's own Spirit. And God has actually given us his Spirit (not the world's spirit) so we can know the wonderful things God has freely given us. *1 Corinthians 2:10-11*
And I will ask the Father, and he will give you another Counselor, who will never leave you. He is the Holy Spirit, who leads into all truth. The world at large cannot receive him, because it isn't looking for him and doesn't recognize him. But you do… *John 14:16-17*
Oh, there is so much more I want to tell you, but you can't bear it now. When the Spirit of truth comes, he will guide you into all truth. He will not be presenting his own ideas; he will be telling you what he has heard. He will tell you about the future. *John 16:12-13*
4. He empowers and helps us: Our lives as Christians can only be lived with the help of the Holy Spirit.
But you will receive power when the Holy Spirit comes on you;.. *Acts 1:8*
And my speech and my preaching [was] not with enticing words of man's wisdom, but in demonstration of the Spirit and of power. *1 Corinthians 2:4*
Next Paul and Silas traveled through the area of Phrygia and Galatia, because the Holy Spirit had prevented them from preaching the word in the province of Asia at that time.... but again the Spirit of Jesus did not allow them to go there. *Acts 16:6-7*
And the Holy Spirit helps us in our weakness. For example, we don't know what God wants us to pray for. But the Holy Spirit prays for us with groaning that cannot be expressed in words. And the Father who knows all hearts knows what the Spirit is saying, for the Spirit pleads for us believers in harmony with God's own will. *Romans 8:26-27*
5. Speaking in tongues is the evidence of receiving the Holy Spirit: When we speak in tongues, we build up ourselves (innerman) like an edifice and communicate mysteries with God.
And these signs shall follow them that believe; In my name shall they cast out devils; they shall speak with new tongues; *Mark 16:17*
All of them were filled with the Holy Spirit and began to speak in other tongues as the Spirit enabled them. *Acts 2:4*
Then when Paul laid his hands on them, the Holy Spirit came on them, and they spoke in other tongues and prophesied. *Acts 19:6*
While Peter was still speaking these words, the Holy Spirit came on all who heard the message. The circumcised believers who had come with Peter were astonished that the gift of the Holy Spirit had been poured out even on Gentiles. For they heard them speaking in tongues... *Acts 10:44-45*
For anyone who speaks in a tongue does not speak to people but to God. Indeed, no one understands them; they utter mysteries by the Spirit... Anyone who speaks in a tongue edifies themselves. *1 Corinthians 14:2-4*
6. We need to be constantly filled with the Holy Spirit: Praying makes us filled with the Holy Spirit and we are thus in tune with him.
But Stephen, full of the Holy Spirit, gazed steadily into heaven and saw the glory of God, and he saw Jesus standing in the place of honor at God's right hand. *Acts 7:55*
After this prayer, the meeting place shook, and they were all filled with the Holy Spirit. Then they preached the word of God with boldness. *Acts 4:31*
7. He gives spiritual gifts for the profit of the church and produces fruits in our lives.
A spiritual gift is given to each of us so we can help each other. To one person the Spirit gives the ability to give wise advice; to another the same Spirit gives a message of special knowledge. The same Spirit gives great faith to another, and to someone else the one Spirit gives the gift of healing. He gives one person the power to perform miracles, and another the ability to prophesy. He gives someone else the ability to discern whether a message is from the Spirit of God or from another spirit. Still another person is given the ability to speak in unknown languages, while another is given the ability to interpret what is being said. It is the one and only Spirit who distributes all these gifts. He alone decides which gift each person should have. *1 Corinthians 12:7-11*
But the Holy Spirit produces this kind of fruit in our lives: love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, and self-control. There is no law against these things! *Galatians 5:22-23*
*Note*
The special faith, healing and diverse kinds of tongues mentioned here(1 Corinthians 12) are spiritual gifts given at the discretion of the Holy Spirit(in heavy dose) and should not be mistaken with the faith, healing and tongues that is for every believer(Mark 16:16-18 and others).