If someone could only read one book of the Bible, I would urge them to read the Gospel of John. (In fact, every year we hand out many thousands of copies of John in our missions and festivals.)
The reason is because John's Gospel was written to tell us about Jesus, and how we can come to believe in Him as our Savior and Lord: "But these [words] are written that you may believe that Jesus is the Christ, the Son of God, and that by believing you may have life in his name" (John 20:31). In its pages you will discover not only who Jesus is, but what He did to save you from your sins.
More than that, you will discover the greatest truth of all: God loves you, and wants you to be with Him in heaven forever. God made us for Himself–but sin separates us from Him, and unless our sins are forgiven, we have no hope of eternal life. Jesus came into the world for one reason: to save us from our sins.
Don't let another day go by without Christ. By a simple prayer of faith commit your life to Him. The Bible's words are true: "For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life" (John 3:16). This is God's promise to you, and I pray you will make your commitment to Christ today.