“Acts 5:3, 4… indicates that the Holy Spirit is God. What do you think about it?”
Let’s read these verses.
“But Peter said, Ananias, why hath Satan filled thine heart to lie to the Holy Ghost, and to keep back part of the price of the land? Whiles it remained, was it not thine own? and after it was sold, was it not in thine own power? why hast thou conceived this thing in thine heart? thou hast not lied unto men, but unto God.” (Acts 5:3, 4)
Many Trinitarians use these verses as conclusive evidence that the Holy Spirit is a third separate person, or being, called God the Holy Spirit, but that is not what these verses say. According to the Bible, the Holy Spirit is the Spirit of God. “And grieve not the holy Spirit of God, whereby ye are sealed unto the day of redemption.” (Ephesians 4:30) The Holy Spirit is called, “the Spirit of your Father.” Please compare the following verses as evidence of this fact: “For it is not ye that speak, but the Spirit of your Father which speaketh in you.” (Matthew 10:20) Mark wrote, “for it is not ye that speak, but the Holy Ghost.” (Mark 13:11) “The Holy Ghost” is “the Spirit of your Father.”
Jesus said as much when he explained, “But when the Comforter is come, whom I will send unto you from the Father, even the Spirit of truth, which proceedeth from the Father, he shall testify of me.” (John 15:26) The Holy Spirit is the Spirit of God, the Father, which proceeds from Him, through His Son Jesus Christ, to us. Paul wrote, “Not by works of righteousness which we have done, but according to his mercy he saved us, by the washing of regeneration, and renewing of the Holy Ghost; Which he shed on us abundantly through Jesus Christ our Saviour.” (Titus 3:5, 6) When we receive the Spirit of the Father coming to us through His Son, we receive the added benefit of receiving the Spirit of His Son as well. “And because ye are sons, God hath sent forth the Spirit of his Son into your hearts, crying, Abba, Father.” (Galatians 4:6) Jesus said, “If a man love me, he will keep my words: and my Father will love him, and we will come unto him, and make our abode with him.” (John 14:23)
On the day of Pentecost Peter taught the same truth when he preached, “This Jesus hath God raised up, whereof we all are witnesses. Therefore being by the right hand of God exalted, and having received of the Father the promise of the Holy Ghost, he hath shed forth this, which ye now see and hear.” (Acts 2:32, 33) Jesus said, “your heavenly Father [shall] give the Holy Spirit to them that ask him.” (Luke 11:13)
When we realize that the Holy Spirit is the Spirit of the Father coming to us through His Son, Acts 5:3, 4 makes perfect sense. Please read it again and see for yourself.
The word holy is an adjective, providing us with a description of God’s Spirit. God has a Spirit, and His Spirit is holy. To lie to God’s Spirit is to lie to God. That is because His Spirit is Himself, not another person. If I were to lie to your spirit, you would not suppose that I lied to someone other than yourself. Let us be just as reasonable with the Scriptures when they refer to God’s Spirit.
I hope this helps to answer your question.