The subject is not easy. The difficulty comes from the fact that under one name „spirit” there can be different meanings.
The word „spirit” appears in Hebrew under the number: H7307 ruach and in Greek G4151 pneuma.
It has different meanings, which can be divided into several main categories:

• Breath, wind.
• Spirit belonging to a given Character: Spirit of God, Holy Spirit, Spirit of Christ.
• Spirit, as the inner sphere of man – spirit of man.
• Emotional state/mood, e.g. spirit of joy, spirit of mourning.
The word 4151 pneúma means: spirit, wind or breath. The most common translation is: „spirit”.
The Hebrew equivalent: 7307 (rûach) has the same scope of meaning as the Greek word: 4151 (pneúma).
In the Bible we distinguish:
• Spirit, as a separate word.
• Spirit of God.
• Spirit of Christ
• Spirit of YHWH.
• Spirit of truth.
• Holy Spirit.
• Spirit of man.
• Demonic/fallen spirits.
• Others indicating the nature of the Spirit, such as the spirits of prophecy, the spirit of wisdom, the spirit of fear, etc.
Therefore, when discussing a given verse/verses, it is important to read carefully which spirit is being referred to.
Let’s see a few examples.

Spirit in the Old Testament

The Spirit of God was present at creation. He is shown as a Spiritual Person:

„In the beginning, the Gods (430 – Elohim, plural) created (singular) the heavens and the earth. And the earth was formless and void; darkness was over the surface of the deep, and the Spirit of God was hovering/moving over the waters.” – Genesis 1:1-2

The Spirit filled chosen people – prophets and servants of God – enabling them to proclaim the message from God:

„And Moses went out to declare to the people the words of YHWH. Then he gathered seventy elders of the people and stationed them around the tent. And YHWH descended in a cloud and spoke with him. He took from the Spirit that was in Him and gave it to those seventy elders. And when the Spirit rested upon them, they fell into prophetic ecstasy. However, this did not happen again.” – Numbers 11:24-25

The Spirit of YHWH acted through the judge:

„The Spirit of YHWH came upon him, and he judged Israel. And when he engaged in battle, YHWH gave Cushan-Rishathaim, the king of Aram, into his hand, so that his hand prevailed over him.” – Judges 3:10

The Spirit of God prophesied through Saul:

„And when they came from there to Gibeah, he met a company of prophets, and the Spirit of God came upon him (Saul). And he prophesied among them.” – 1 Samuel 10:10

This prophecy foretold that the Messiah would be endowed with the fullness of the Spirit:

„And a shoot will come forth from the stump of Jesse (father of King David), and a branch will grow from his roots. And the Spirit of YHWH will rest upon Him—the spirit of wisdom and understanding, the spirit of counsel and might, the spirit of knowledge and the fear of the Lord.” – Isaiah 11:1-2

„Draw near to Me, listen to this: I have not spoken in secret from the beginning; since it came to pass, I was there. And now the Lord YHWH has sent Me with His Spirit / has sent Me and His Spirit.” – Isaiah 48:16

„He said: Surely they are My people, children who will not be false to Me! And He became their Savior in all their distress. It was not a messenger or an angel, but His own presence that saved them. In His love and mercy, He Himself redeemed them. He took them upon Himself and carried them all the days of old. But they rebelled and grieved His Holy Spirit. So He turned against them as an enemy; He Himself fought against them.” – Isaiah 63:8-10

Spirit in the New Testament

Sin Against the Holy Spirit:

„I declare to you that all sins will be forgiven to the sons of men, and blasphemies, if they blaspheme/scoff/defame/revile (987). But whoever blasphemes/scoffs/defames/reviles (987) against the Holy Spirit has no forgiveness for the ages (eons), but is guilty of eternal/aionic judgment.” – Mark 3:28-29

Spirits sent by Christ:

„But the Helper, the Holy Spirit, whom the Father will send in My Name, He will teach you all things and will remind you of everything I have told you.” – John 14:26

„When the Helper/Comforter comes, whom I will send to you from the Father— the Spirit of Truth who proceeds from the Father—He will testify about Me.” – John 15:26

„You heard that I said to you: I am going away and I am coming to you. If you loved Me, you would rejoice that I am going to the Father, because the Father is greater than I.” – John 14:28

A spirit sent as a messenger, the messenger is lower in the hierarchy than the sender:

„Amen, amen, I say to you, a servant is not greater than his master, nor is a messenger (apostle) greater than the one who sent him.” – John 13:16

Spirits of prophets:

„And the spirits of the prophets are subject to the prophets. For God is not a God of disorder, but of peace—as in all the assemblies (congregations) of the saints.” – 1 Corinthians 14:32-33

The Spirit of man

„For who among men knows the things of man, except the spirit of man which is in him? So also, the things of God no one has known, except the Spirit of God.” – 1 Corinthians 2:11

„The burden. The word of YHWH concerning Israel. The declaration of YHWH, who stretched out the heavens, laid the foundations of the earth, and breathed the spirit into the inner part of man.” – Zechariah 12:1

„But it is the spirit in man, the breath of the Almighty, that teaches him/gives him understanding.” – Job 32:8

„And they mocked Him, knowing that she was dead. But He, having put them all out, took her hand and called out, saying: 'Little girl, arise.’ And her spirit returned, and immediately she stood up, and He commanded that she be given something to eat.” – Luke 8:53-55

„For those who are led by the Spirit of God are the children of God. For you have not received the spirit of slavery to fall again into fear, but you have received the spirit of sonship, by which we cry out: Abba, Father! This very Spirit testifies with our spirit that we are children of God.” – Romans 8:14-16

„After recognizing Peter’s voice, out of joy she did not open the gate, but ran in and announced that Peter was standing at the gate. But they said to her, 'You are mad!’ Yet she insisted that it was so. To which they responded, ’It is his angel.’” – Acts 12:14-15