Revelation 13:5: And there was given unto him a mouth speaking great things and blasphemies; and power was given unto him to continue forty and two months.

In Revelation 13:5, there was given unto him a mouth. Many scholars identify the First Beast as the him to whom the mouth was given¹ by the Dragon in Revelation 13:2.² However, Revelation 13:4 mentions worship of both the Dragon and the First Beast,³ so the him in verse 5 could be the Dragon, the First Beast, or even both‒although the verse does not say a mouth was given to them both. Nevertheless, both may be intended since the Dragon gave his seat and great authority to the First Beast in Revelation 13:2, including a mouth to speak blasphemies throughout the Roman Empire. However, God also, and separately, gave Satan (the Dragon) a mouth to speak blasphemies beyond the geographical limits of the Roman Empire, in places such as America and among the Lost Ten Tribes of Israel.

The image of the First Beast in Revelation 13:1-4 is specific to the Imperial Roman Empire and the Holy Roman Empire that emerged after the fall of Rome in 476 AD.⁴ Thus, if the Dragon (Satan)⁵ gave a mouth to the First Beast, then the power of that mouth, would be limited to kingdoms and peoples within the ancient Roman Empire.⁶ This conflicts with Revelation 13:7, which states that power was "given him over all kindreds, and tongues, and nations."⁷ Revelation 13:8 likewise states that, "all that dwell upon the earth shall worship him."⁸ Since the mouth of him in Revelation 13:5-8 had power to overcome the saints throughout the entire earth,⁹ it appears that Satan is the him to whom a mouth was given by God in Revelation 13:5.¹⁰ However, the First Beast received his power from Satan and was, therefore, the mouth of Satan within the confines of the Roman Empire.¹¹

The him in Revelation 13:5-8 is similar to the little horn that was given a mouth in Daniel chapter 7.¹² Daniel's vision was not limited to the Roman Empire. His vision indicates that the little horn is the latter-day kingdom of Satan that grows until Satan's mouth has achieved worldwide power and influence.¹³

Satan also had to be the him that was given a mouth¹⁴ during centuries of spiritual darkness called the Dark Ages,¹⁵ which were one part of the Great Apostasy that became universal in all the world.¹⁶ However, the Great Apostasy began with the death of the apostles in Christ's primitive church within the Roman Empire.¹⁷ During the Great Apostasy, Satan's mouth gave him unfettered power¹⁸ and destructive influence¹⁹ throughout the world.²⁰ The First Beast (Roman Empire) was, therefore, Satan's mouthpiece²¹ that destroyed Christ's church on the eastern hemisphere.²² The Gadianton Robbers were Satan's mouthpiece that destroyed the entire Nephite civilization on the western hemisphere.²³ Throughout the Great Apostasy Satan's mouth had power to speak great things and blasphemies²⁴ with worldwide effect.

Revelation 13:5 defines the timing of the universal Great Apostasy as a period of forty and two months.²⁵ The 42 months is a prophetic period of evil that equates to 3½ years.²⁶ In this context, the time is also equal to 1260 days (42 months x 30 days each).²⁷ However, the 1260 days are also prophetic days of years, which means the Great Apostasy lasted 1260 years according to John's reckoning of time.²⁸ Since John's account is chronological, the 1260 years in Revelation 13:5 began after the events he described in Revelation 13:3-4, which include the fall of the Roman Empire in 476 AD in verse 3 and the establishment of papal power in the Holy Roman Empire no later than 607 AD in verse 4.²⁹ Therefore, according to John's chronological account, the Great Apostasy began in Revelation 13:5 no later than 607 AD.

The start date for the 1260 years of Great Apostasy can be precisely determined because John measured the Great Apostasy based on the presence or absence of priesthood authority on the earth.³⁰ By this measure, the Great Apostasy began slowly as Christ's ancient apostles were killed in the first century AD.³¹ However, from John's visionary perspective, the 1260 years of apostasy officially began when the priesthood of God³² was no longer administered by mortals anywhere on the earth³³ among any group of people.³⁴

John's method of measuring 1260 years of Great Apostasy based on priesthood authority differs from Daniel's method of measuring 1290 years of Great Apostasy based on a flood of spiritual darkness.³⁵ In Daniel's vision, the flood of spiritual darkness³⁶ began when the temple was destroyed in Jerusalem in 70 AD.³⁷ That flood of darkness continued as a Great Apostasy for 1290 years until 1360 AD.³⁸ That year corresponds in time with the start of the Renaissance.³⁹ At that point in time, the power of the papacy began to decline.⁴⁰ The Dark Ages had then reached their zenith of spiritual darkness like flood waters that had crested and the first rays of spiritual light began to emerge on earth dispelling centuries of spiritual darkness.⁴¹

Daniel's flood of spiritual darkness began in 70 AD, but priesthood authority was still on the earth for several centuries. For example, John still administered apostolic authority when he wrote the Book of Revelation in 96 AD,⁴² and at least seven branches of the ancient church still existed.⁴³ On the other side of the world, Christ had other sheep that also held and administered the priesthood after his resurrection.⁴⁴ These other sheep, called the Nephites, continued to have mortal priesthood holders in their midst until they apostatized⁴⁵ and were finally destroyed in about 420 AD.⁴⁶

The Lost Ten Tribes were the only other (known) group⁴⁷ of Israelites⁴⁸ that legally administered the priesthood⁴⁹ on earth after Christ's resurrection.⁵⁰ Their priesthood administration on earth ceased, however, when they were translated.⁵¹ Assuming the Lost Ten Tribes were the last legal administrators of the priesthood on the earth after the resurrection of Jesus Christ,⁵² then their translation must have occurred in 570 AD.⁵³ That date is 1260 years before The Church of Jesus Christ of Latter-day Saints was restored in 1830.⁵⁴ Angels of God literally restored the priesthood⁵⁵ so that mortal priesthood holders were again on the earth⁵⁶ and could legally administer the gospel of Jesus Christ beginning in 1830.⁵⁷