Romans 8:5 says, “For those who are according to flesh mind the things of the flesh; but those who are according to spirit, the things of the Spirit.” We need to ask what the things of the Spirit are. John 16:12 through 15 shows us what they are. These verses reveal that whatever the Father is, is the Son’s. The Son inherits all the riches of the Father. Then whatever the Son is, is received by the Spirit. Finally, the Spirit discloses all these things to us. Based upon John 16:12 through 15, the things of the Spirit in Romans 8:5 must be the things concerning Christ. Therefore, the Spirit has the function of conveying the things concerning Christ.
The Spirit functions as the reality and reaching of God (Rom. 8:9a). The Father is embodied in the Son, and the Son is realized as the Spirit. Eventually, the Father, the Son, and the Spirit are fully realized as the Spirit. The Spirit is the reality of the Triune God, and the Spirit reaches us. The reaching is the application of the Triune God. The Triune God is realized as the Spirit and applied to us as the Spirit.
The Spirit is the reality and person of Christ (Rom. 8:9b). Romans 8:9 speaks of the Spirit of God and the Spirit of Christ. These two terms are interchangeably used. This means that the Spirit of Christ is the Spirit of God. This Spirit is Christ’s reality and Christ’s person.
Romans 8:11 reveals three functions of the Spirit: resurrecting, life-giving, and indwelling. Romans 8:11 says, “But if the Spirit of Him who raised Jesus from among the dead dwells in you. He who raised Christ Jesus from among the dead will also give life to your mortal bodies through His Spirit who indwells you.” The Spirit resurrects us by giving life to us, and the life-giving Spirit gives us life by indwelling us. His indwelling is for life-giving, and His life-giving carries out the resurrecting. We need these functions of the Spirit daily.
Romans 8:14 says, “For as many as are led by the Spirit of God, these are sons of God.” The Spirit functions in the believers by leading them to live a life as sons of God. We know that we are sons of God because we are led by the Spirit. This leading is not accidental or occasional. Rather, the leading of the Spirit should be habitual, constant. Continuously in our daily living we should be led by the Spirit. If we are continually led by the Spirit, we are living as sons of God in a practical way.
The Spirit also has the function of witnessing. Romans 8:16 says that the Spirit witnesses with our spirit that we are the children of God. In Romans 9:1 Paul said that his conscience bore witness with him in the Holy Spirit. The Spirit is witnessing that we are the children of God. Many sisters have the experience that even while they are shopping in a department store, there is a witnessing within them reminding them that they are the children of God. Sometimes while a husband is losing his temper with his wife, there is also a witnessing—“Don’t forget that you are a child of God.” Nothing stops a person’s temper as fast as saying amen to this kind of witnessing in his spirit. The witnessing Spirit within our spirit witnesses that we are children of God.
Romans 8:23 speaks of the Spirit being the firstfruit (foretaste) of God as our portion. The firstfruit is the first taste, the foretaste. God is our eternal portion. He is enjoyable and tasteful. The Holy Spirit, the all-inclusive Spirit, is the firstfruit of all the riches of God for our enjoyment. What we have enjoyed and what we are still enjoying of God Himself is just a foretaste. The full taste is coming. We will enjoy the full taste of God at the redemption of our body.