The number 666 is called "the number of the beast" in the book of Revelation and is associated with a figure who opposes God during the end times. The Bible says, "Here is wisdom. Let him that hath understanding count the number of the beast: for it is the number of a man; and his number is Six hundred threescore and six." (Revelation 13:18, KJV). Throughout Scripture, the number 7 is often connected with completeness or fullness, while 6, falling short of 7, has been understood by many Christians as representing human imperfection or incompleteness. The repetition of 666 is therefore commonly interpreted as emphasizing humanity's rebellion, self-exaltation, or the ultimate opposition to God embodied by the beast. Others have proposed that the number may refer to a specific historical ruler through a practice known as gematria, in which letters have numerical values. Because Revelation uses vivid symbolic imagery, Christians differ on the precise interpretation of 666, but they broadly agree that the passage warns believers against allegiance to evil and calls them to remain faithful to Jesus Christ.