The flesh and the spirit are the real keys to our spiritual life and church life. If we mean business with the Lord for the Christian life and the church life, we have to see the flesh and the spirit. We need to realize that our flesh has been thoroughly polluted and corrupted by Satan's presence. Regardless of how good we may be, our flesh is corrupted with Satan. But thank God that with all the fallen human beings, God has reserved the human spirit for His purpose.
It is as if God has drawn a borderline to encircle the human spirit and protect it from the corruption of the devil. This principle can be fully illustrated by the case of Job. God let Satan damage Job, but He told Satan that there was a line. Satan was allowed to go only so far. God would not let him go any further (Job 2:4-6). I believe that God did the same thing with Satan concerning the human race. God allowed Satan to damage the human race, but He allowed him to go only so far. Satan got into the human body and damaged the human soul, but God preserved the human spirit for Himself.
If we consider our past before we were saved, we can realize that although our flesh was so bad, deep within us there was another part preserved by God. When people are acting in the lusts of the flesh, something deep within them is saying, "You shouldn't do this. This is not right." This is the voice out of the section of their being preserved by God.
Today, with us, the saved ones, the principle is even more clear. The lusts in your flesh may urge you to go to the movies or to the department store. While you are being urged to go, there is another section of your being deep within you telling you not to go. Deep within the Lord may say, "Do you really mean that you love Me? Don't you remember the meeting in which you stood up and told people you consecrate yourself to Christ and the church?" We do have the ugly flesh, but we also have a wonderful spirit. One part, our flesh, is fully possessed by Satan. The other part, our spirit, is kept by the Lord and for the Lord.
We must have a thorough discernment of what the flesh is and what the spirit is. A brother's wife may prepare a meal for him which is not so good. This offends him. Strictly speaking, this offended his flesh. When you are offended in your flesh, you will immediately react. But the inner part of this brother's being would say Hallelujah to his dear wife. There is a struggle between the flesh and the spirit (Gal. 5:16-17). If a brother sides with the lust in his flesh, he will argue with his wife. If he remains in his spirit, he will say, "Praise the Lord! Jesus is Lord, even if my meal is not so good."