1 John 5:7 is probably the most controversial inclusion in the King James translation of the Bible. Often referred to as the Johannine Comma (Latin: Comma Johanneum), entire books have been written about this one verse, either for or against its place in the Biblical text. It is arguably the most concise Trinitarian declaration in the New Testament:

For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one.