Such a spirit is for us to receive God as life and to express Him (Gen. 2:9b; 1:27). We are living on this earth for the purpose of receiving God and expressing God.
Eventually, we can be joined to God as one spirit (1 Cor. 6:17). In the whole universe, nothing can be higher than to be joined to God as one spirit. The divine Spirit and the human spirit become one spirit. If all human beings were joined together with God as one spirit, the earth would become heaven! The earth is full of bad news because people live by their soul with their body. But we need to be those who live by our spirit with the Spirit.
Our spirit is composed of the conscience, the fellowship, and the intuition. For a further discussion of the functions of our spirit, see pages 56-59 of The Economy of God.
In Romans 9:1 Paul said that his conscience bore witness with him in the Holy Spirit. Romans 8:16 says that the Spirit witnesses with our spirit. On the one hand, the Holy Spirit bears witness with our spirit. On the other hand, our conscience bears witness with the Holy Spirit. This shows that the conscience is a function of our spirit. If we neglect our conscience, our spirit cannot function properly to contact the Spirit. We must learn to take care of our conscience. The conscience regulates us by either condemning or justifying us. Our inner justification and inner condemnation is by our conscience in our spirit.
The fellowship is another function of our spirit. John 4:24 says God is Spirit and those who worship Him must worship Him in spirit. To worship Him means to fellowship with Him. If you are going to fellowship with God, you must do it in your spirit. Outside of the spirit, there is no fellowship with God. In Romans 1:9 Paul said that he served God in his spirit. To serve God is to fellowship with God. The servants and the master always contact each other. They always fellowship. We serve God, our Master, by contacting Him, fellowshipping with Him, in our spirit. Luke 1:47 says, "My spirit has exulted in God my Savior." To exult in God, to be joyful in the Lord, is also a kind of fellowship.
First Corinthians 2:11 says that only the spirit of man knows the things of man. This is a direct knowledge from the intuition. Mark 2:8 tells us that even the Lord Jesus, while He was on this earth, perceived in His spirit. He had the Holy Spirit with Him, but He also was a man with His own spirit. He had the inward intuition in His spirit to directly perceive things.