Johannine Comma Explained Simple but in Detail: Father, the Word, and the Holy Ghost

The so-called Johannine Comma (also called the Comma Johanneum) is a sequence of extra words, which appear in 1 John 5:7-8 in some early printed editions of the Greek New Testament.

These extra words are generally absent from the Greek manuscripts. In fact, they only appear in the text of four late medieval manuscripts. They seem to have originated as a marginal note added to certain Latin manuscripts during the Middle Ages, which was eventually incorporated into the text of most of the later Vulgate manuscripts.