Some people think that the Holy Spirit is a person, but let’s look at how the word “spirit” is used in the Bible. In the Old Testament, “spirit” is the Hebrew word ruach which is literally translated as “wind or breath” such as in Genesis 1:2: “The Spirit of God moved upon the face of the waters.” In the New Testament, the Greek word for “Spirit,” or “Ghost,” in the expressions Holy Spirit or Holy “Ghost,” is pneuma which also means wind. When Jesus was baptized in Luke 3:22 it says, “And the Holy Ghost descended in a bodily shape like a dove upon him…”
Wind is both invisible and powerful, hence the ancients applied this word to various invisible and powerful influences. Since divine power is exercised through channels and by agencies beyond human sight and understanding, these words ruach and pneuma came to be applied more and more to all of God’s dealings.
The Holy Spirit, then, is the invisible power of God, a power that is manifested in a great variety of ways. The influence of the Holy Spirit in a Christian’s life is the power of God transforming his heart and mind into Christlikeness. Paul gives us a beautiful description of this work of the Spirit, saying, “Be renewed in the spirit of your mind; … put on the new man, which after God is created in righteousness and true holiness,” (Ephesians 4:23,24). And again, “The fruit of the Spirit (pneuma, God’s power) is in all goodness and righteousness and truth,” Ephesians 5:9.
So how do we receive this influence of God in our lives? We follow the instructions given by Paul. When a person accepts Christ as his Savior (Acts 4:12) and gives up his own will in full consecration to do the will of God (Hebrews 10:9, Matthew 16:24), God shows that person’s adoption as a son of God by begetting him with the Holy Spirit (Ephesians 5:18). From that time onward, the Spirit continues to energize his life and mind, and to promote the growth of the Christian graces of “peace, joy, longsuffering, brotherly kindness, and love,” (Galatians 5:22, 23 and 2 Peter 1:5-7).
Please note: some Christians confuse Spirit begettal with the miraculous gifts of the Spirit. Those miraculous gifts ended with the death of the apostles. See the question: “What are the gifts of the spirit?”