Over the last few days, we have been talking about the Lord Jesus' ascension back to sit at the right hand of the Father and what He has commanded us to do while we wait for His return. God longs for the knowledge of Christ's substitutionary death to reach out to all the earth. Here’s what Jesus said: “Therefore go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit” (Matthew 28:19).
I spent a lot of time at sea as a commercial fisherman in my younger years. When you are out there in one of the busiest shipping lanes in the world, the Dover straits of England, you get to see all kinds of ships and boats designed for all sorts of jobs. But for us fishermen, our purpose was to catch fish. It would have been easy to waste time on things our boat was not designed for. Now that God has called me to work on His net, I don't want to get to the end of my life and find that I invested my life doing things that wasted a lot of time, energy, and money. The main thing we are called to do must be the main thing! What is the primary charge given by the Lord to the Church of Jesus? Paul says that it is the gospel, "For I am not ashamed of the gospel, because it is the power of God that brings salvation to everyone who believes: first to the Jew, then to the Gentile" (Romans 1:16). When presented correctly and believed, the gospel of Jesus Christ brings about a radical change at the spirit level of every true believer in Christ. Paul, in the passage above, called it the power of God. Without this encounter with Christ, there is no change inside a person:
And he said: "Truly I tell you, unless you change and become like little children, you will never enter the kingdom of heaven” (Matthew 18:3).
Every effort of the Church must be to preach the gospel to bring about this change in people's hearts worldwide. Some people believe that if they work hard at reforming their lives and live according to the Ten Commandments, that is being a Christian. Let me tell you something important: You cannot become a Christian by living the Christian life. We don't have the ability in and of ourselves to do what God told us to do. Christ living in us and working through us is the only One who can live the Christian life. The Spirit of Christ lives in us to enable us to do what He expects of us. Here is how Merrill Tenney put it,
Christianity is not a system of philosophy, nor a ritual, nor a code of laws; it is the impartation of divine vitality. Without the way there is no going; without the truth, there is no knowing; without the life, there is no living.
You must have Christ in you, living and seated on the throne room of the temple of your life. “God has chosen to make known among the Gentiles the glorious riches of this mystery, which is Christ in you, the hope of glory” (Colossians 1:27). We can help feed people, we can teach them to have better marriages, we can bring them into a community with others, but if we do not help them to see that they need the main thing—to be reconciled to God (2 Corinthians 5:20), all our efforts are for nothing. We must bring them to Christ to receive the gift of eternal life! The main thing is to help each person be born-again of the Spirit and live the life of Christ. This calling is not the job of the professionals or the gifted leaders; it is the job of all who call on the name of Christ. I am convinced that if we can help each Christian to learn how to share the gospel, a revival will break out worldwide in scope. God wants to use His people to reach out to our towns and cities, neighborhoods, state, country, and world with the gospel. We should all know how to share the gospel and bring hope to a sinful world:
But in your hearts revere Christ as Lord. Always be prepared to give an answer to everyone who asks you to give the reason for the hope that you have (1 Peter 3:15).
Taken from the series in Discipleship, Study 7. The Main Thing
 Merrill C. Tenney, John: The Gospel of Belief (Grand Rapids, Mich: William B. Eerdman's Publishing Co., 1948) Pages 215-216.