THE WRITING SPIRIT
Second Corinthians 3:3 says, "Since you are being manifested that you are a letter of Christ ministered by us, inscribed not with ink but with the Spirit of the living God; not in tablets of stone but in tablets of hearts of flesh." The Spirit is the writing Spirit, and we are the letters of Christ. The Spirit is the ink for writing Christ into us. As the divine ink, the Spirit is the Spirit of the living God. There should be something living within us all the time as evidence that Christ is being written into every part of our inner being. If we are under the Spirit's writing, we have the deep sensation of being living within. Christ is being written into us with the spiritual ink, the Spirit of the living God. This makes us a letter of Christ. All of us should be such a living letter of Christ, that others may read and know Christ in our being. We are under the writing of the Spirit of the living God, and He is engraving Christ into us.
THE LIFE-GIVING SPIRIT
In 2 Corinthians 3:6 Paul said that the letter kills but the Spirit gives life. This means that the Spirit inwardly imparts life into us day by day. We need to always return to our spirit because it is in our spirit that we sense and experience the imparting of life. This revives us and makes us living. If we pay attention to the letter of the Bible, we will be killed. We do not need the regulating of the letter, because we have the regulating of the Spirit within us.
Paul, of course, wrote the church in Corinth with the background of Judaism. Those in Judaism became stuck to the written code of the Old Testament according to the letter. But Paul came and told them something different from this written code. Their eyes were veiled with this written code, so they opposed Paul. They could not see Jesus, the Spirit, or any of the spiritual things, because they were veiled. So the apostle Paul told them that the letter kills. It is the Spirit who gives life, and the Lord is the Spirit (v. 17). They needed to take away all the veils, which means that they had to get rid of their old knowledge of the written code.
In principle it is the same today. Today's Christianity is like Judaism in the sense that the ones there stick themselves to the written code of the Bible, which kills, and not to the living Spirit, who gives life. It is pitiful to keep ourselves under the dead letter, the written code of outward regulations. All the veils of our old knowledge of old doctrines according to the dead letter need to be taken away. We need an unveiled, open face to look at the Lord directly. We care just for the Spirit, not for any doctrinal teaching.
(The Experience of Christ as Life for the Building Up of the Church, Chapter 8, by Witness Lee)