We often see signs and banners at sporting events that say "John 3:16." Wrongly so, John 3:16 is often written as graffiti on highway overpasses. Some "entertainers" have thrown in a twist and replaced "John" with "something else 3:16." So, what is the big deal with John 3:16? Why is this one verse so important?
No other verse in the Bible so succinctly summarizes God's relationship with humanity and the way of salvation. Some consider John 3:16 as the "theme verse" for the entire Bible. John 3:16 tells us of the love God has for us and the extent of that love—so great that He sacrificed His only Son on our behalf. John 3:16 teaches us that anyone who believes in Jesus Christ, God's Son, will be saved. John 3:16 gives us the glorious hope of eternal life in heaven through the love of God and death of Jesus Christ.
Read more: http://www.gotquestions.org/John-3-16.html