If the Holy Spirit is in our spirit, then where is Christ? He is in the Holy Spirit. Not only is He in the Holy Spirit, but He is the Holy Spirit! First Corinthians 15:45 states, "The last Adam [which is Christ] was made a quickening spirit." The word "quickening" means life-giving. Christ was made a life-giving Spirit. Could this life-giving Spirit be any other than the Holy Spirit? Of course not. Second Corinthians 3:6 says, "The Spirit giveth life." Who is this Spirit that gives life? The answer is in verse 17 of the same chapter: "Now the Lord is that Spirit." So Christ, the Lord, is the Spirit that gives life. This is indeed wonderful! Christ is the Spirit, we have a spirit, and these two spirits are joined as one. How can we contact Christ? By the spirit! The only way for us to contact Christ is to exercise our spirit, because Christ is now the Spirit, and this Spirit is the Holy Spirit in our spirit. If we exercise our spirit, we can contact Christ. This is the secret.
Since Christ, as the life-giving Spirit, dwells in our spirit, we need to discern our spirit from our soul that we may contact and experience Him. We may know that man is composed of the spirit, soul, and body, but to discern the difference between the spirit and the soul is a real problem. To know the difference between the body and the soul is easy, but to discern the spirit from the soul is rather difficult. The following illustration is most helpful. Suppose we find something that we would like to purchase. The more we consider it, the more we feel that we would like to have it. Eventually, we make the decision to buy it. The emotion is exercised, since we like it; the mind is exercised, because we have considered it; and the will is exercised, because we have made the decision to buy it. Therefore, the whole soul is exercised. But when we proceed to buy it, something very deep within us protests. Our emotion likes it, our mind considers it, and our will chooses it; but something deeper than all these protests. This is the spirit. The spirit is the deepest part within us, the very inmost part of our whole being. It is absolutely different from our soul.
In our body we have the physical life as mentioned in Luke 8:14. In our soul we have the psychological life, that is our human life, as mentioned in Matthew 16:25. In our spirit we have the spiritual life, that is the divine life, the eternal life, as mentioned in John 3:16. The unbelievers have only physical life in their body and human life in their soul. They do not have the eternal life of God in their spirit, because they have not received Christ as life into their spirit. Therefore, they can only live by the body and by the soul. Sometimes they act according to their flesh, and sometimes they do things by desiring, by reasoning, and by choosing. This means they are living by their body and by their soul. They are not able to live by their spirit. But those of us who have received Christ into our spirit can live by our spirit with Him as our life. We can say that I have been crucified, and it is no more I, but Christ that lives in me (Gal. 2:20). The Greek word for "I" is "ego," which is the soul, the self. Our soul, the self, has been crucified and put to death, and there is no more "I," but Christ that lives in our spirit. Thus, we can and must live in our spirit, since Christ is living in it.
We must first realize that Christ is the Spirit in our spirit. Then we need to discern the difference between the spirit and the soul that we may deny the soul and live by the spirit. When we live by the spirit, Christ will have the first place in everything. Then we will experience Christ in the spirit, and we will learn how to apply Him in our daily life.
(The Parts of Man, Chapter 1, by Witness Lee)