God empowers and enables
There is great joy in the fact that the message Christians share is God's message. It hasn't changed in 2000 years. He also empowers and enables believers to share the good news, by giving us the Holy Spirit. You can read all about what Jesus said about the Holy Spirit in John's Gospel from Chapter 14 onwards. The next book in the Bible after John's Gospel is 'the book of Acts' or 'the Acts of the Apostles'. That's a historical account from a doctor called Luke, who describes the miracles and messages of the first followers of Jesus as Christianity spread out from Jerusalem after the resurrection of Jesus.
The book of Acts is a great read. One thing of note in there is the importance and the necessity of receiving the Holy Spirit from Jesus. When He gives us His Spirit, He empowers and enables us to be His ambassadors. That's what He wants for all Christians, not just a few, but all.
Jesus Promises Living Water to Anyone
On the last day of the feast, the great day, Jesus stood up and cried out, “If anyone thirsts, let him come to me and drink. Whoever believes in me, as the Scripture has said, ‘Out of his heart will flow rivers of living water.’” Now this he said about the Spirit, whom those who believed in him were to receive) John7.37 esv