Many people begin to question what God has done in the New Covenant when their experience does not seem to match up with the truths we have just considered. There may be several reasons for the disparity.
It may be that a person has not actually begun in the Spirit. To begin with God is more than just "believing in Jesus." The devils also "believe and tremble," as stated in James 2:10, but the devils do not know fellowship with God. Many will say they believe in Jesus, but the belief they speak of is an intellectual belief. They find comfort in the fact that they believe the "right things." Some find great comfort in defending the Bible, being absolute about certain truths, and doing certain right things such as attending church meetings. Some even sacrifice their lives to do service for God.
Many beliefs are correct, and God does call men into His service, but doing any of these things does not mean we have begun in the Spirit or that we are alive to God. It may safely be said that the vast majority of people around the world who are "doing work for God" do not even know God. They will be among those of whom Jesus spoke in Matthew 7:21-23, who will say they have done great wonders in His name--but Christ will say, "I never knew you, depart from Me. " Lest these words be said to us, we must be diligent to know Him.
A beginning in the Spirit is not a simple belief in Jesus, but a divine transaction with God which is spoken of as being "born again." Read John 1:12,13 very carefully. We must first believe in Jesus or we will never come to Him. But when we truly come to Him, He will baptize us with the Holy Spirit (Luke 3:16). Jesus said that the result of believing in Him would be "rivers of living water," and that this spoke of the Holy Spirit who would come when Jesus was glorified (John 7:37-39). The rivers began on the day of Pentecost (Acts 2) but the promise was not only to the first believers, but also to those of us who were "far off" (Acts 2:39). The believers in Jesus were baptized into His life on that day for the first time. It was a life-changing experience. They began in the Spirit--they were born again. The fruits that followed bore witness to this. Before that day, Peter ran from a slave girl; now he stood before all Jerusalem with great boldness and called its leaders murderers of the Christ.
Other accounts of men being born of the Spirit in the book of Acts record evidence of the divine presence. Encounters with God do not leave a man the same. Birth is cataclysmic. It takes us from one realm to another. To be taken from the natural to the spiritual is no small transaction. The question is, have we begun in the Spirit? If not, we cannot walk in the Spirit and we will not know the power of an endless life. Christianity to us will be a mere intellectual exercise of trying to believe the right things and "doing the best we can." The best we can do will never meet the requirements of a holy God. His requirement is perfection, and only God is perfect. Therefore, the only way we can measure up to God's requirements is to have the life of God within, being lived out in us. This is not a theoretical or positional hope, but an experiential reality to the one walking in faith.