The Gospel of John is one of the most popular books of the Bible for evangelism. Why? Because this is the one book of the Bible written primarily to those who have not yet believed in Jesus Christ. While the rest of the Bible speaks mainly to those who know Christ, John has in mind those that do not know Him. As an eyewitness to the events of Jesus' life, John selects and presents the most convincing words and works of the One who claimed to be the Son of God to those who need eternal life: "And truly Jesus did many other signs in the presence of His disciples, which are not written in this book; but these are written that you may believe that Jesus is the Christ, the Son of God, and that believing you may have life in His name."

(John 20:30-31)