Because the Bible testifies to the number 666 as the number of Satan, many churches are doing a lot of research to find out what 666 really is. The Church of God claims that the letters Vicarius Philadelphi, which are inscribed on the crowns made by the popes, translate to the Latin number 666, but this is an ignorant claim that does not know the Bible. The secret of 666 is not to be found outside the Bible, but within it, and all secrets are found in the Bible. To know the reality of 666, we must know the history of physical Israel beginning with David. The book of Revelation is sealed, as is the book of Daniel. In the book of Daniel, the history from the liberation of Babylon to the establishment of the independent Hasmonean dynasty is sealed, but it is a type and shadow of spiritual Israel starting with Jesus, so when you know the sealed history, you know the reality of 666, which is manifested in the history of spiritual Israel.  

In the history of Israel as recorded in the book of Daniel, there are two little horns that afflict God's people and cause them to worship idols: one is Babylon, which appeared in 600 B.C., and the other is Antiochus IV, King of Syria, which appeared in 170 B.C. However, this is not just the history of physical Israel, but a shadow of the spiritual Israel that will emerge, beginning with Joshua on David's throne. The first little horn to appear in the history of spiritual Israel is Catholicism, and Catholicism has fulfilled the prophecy of spiritual Babylon. God characterized Catholicism by describing it as a beast with seven heads and ten horns. 

[Revelation 13:1] I looked and saw a beast coming up from the sea. This one had ten horns and seven heads, and a crown was on each of its ten horns. On each of its heads were names that were an insult to God. 

Therefore, we need to know the history of fleshly Israel that began with David. If you do not know the history of physical Israel, you do not know the reality of 666 and you do not know the history of spiritual Israel. The history of physical Israel that began with David and the history of spiritual Israel that began with Yehoshua are as follows. 

1) Just as David built the temple site, Yehoshua, who sat on the throne of David, laid the temple site called the 12 apostles. 

2) Just as Solomon, the son of David, completed the temple, Yehoshua gave the Holy Spirit to the disciples and made the body of the saints the temple. And through them, the early church was established. 

3) At the end of Solomon, the kingdom was divided into two kingdoms due to Solomon's idolatry. Likewise, when heresy was introduced at the end of the Early Church, it was divided into the Eastern Church, which was built around Jerusalem, and the Western Church, which was built around Rome. 

4) Northern Israel continued to worship idols after division and kept God's feasts differently, and eventually they were destroyed by Assyria. Likewise, at the end of the early church, the divided Western church colluded with the Roman emperor and absorbed various pagan doctrines, and it was severely corrupted. 

5) After division, Judah in the south practiced idolatry, but sometimes obeyed God's will and was protected from foreign invasion. But they were destroyed by Babylon because of the corruption of the priests and leaders. Likewise, the Eastern Church, which was divided at the end of the Early Church, sometimes obeyed the Word of God and kept its purity, but eventually it was merged with the Western Church and deteriorated greatly. 

6) Northern Israel and Southern Judah were captured by Babylon and spent 70 years in captivity, and many became slaves. Likewise, after the Eastern and Western churches became one, they became pagans and started anew as a religious organization called Catholicism. As a result, many saints were killed by Catholic witch hunts and the Inquisition. 

7) With the help of the Medes and Persians, Israel was liberated from the Babylonian captivity and returned to the mainland to build a temple. However, this prophesied the destruction of Catholicism represented by Babylon. For over a thousand years, Catholicism has killed and harassed tens of millions of people through the Inquisition and witch hunts. As such, the fall of Babylon by the Medes and Persians showed that the evil deeds of Catholicism would be put to an end by Reformers such as Luther and Calvin. The Reformation freed many believers from Catholicism and allowed them to join Protestantism in search of freedom of faith. However, this fulfilled the prophecy that Israel was not independent but was under Persian rule. 

8) Israel was ruled by the Persian Empire for 200 years before being ruled by Alexander the Great, who destroyed Persia in 333 BC. However, this shows that believers absorbed into Protestantism after the Reformation will be disappointed and leave Protestantism. Many Protestants zealously followed the Adventist ideas of William Miller, which emerged in 1834. During the decade, he had gathered numerous followers across Europe and America, but his proposed date for the Second Coming of Joshua failed. This event resulted in the wastage of many people's fortune and was a fulfillment of prophecy that Alexander would rule Israel after Persia. 

9) When Alexander the Great died at a young age, Greece was divided into four kingdoms, and Israel was ruled by that kingdom. But this represents a prophecy that will happen after William Miller. Those who were disappointed with Miller were absorbed by the Adventist Church, Jehovah's Witnesses, and the Legalist Church. Those churches were the ones that followed Miller's ideas. However, this was the fulfillment of a prophecy that after the death of Alexander the Great, natural Israel would be ruled by the four divided nations of Greece. 

10) Although the four divided kingdoms of Greece continued to dominate Israel, Israel was eventually slaughtered by the religious oppression of Antiochus IV, king of Syria, who appeared in 170 BC. However, this prophesied the church that would appear after the Adventists, Jehovah's Witnesses, and the legalistic church of the Old Testament. Like Antiochus IV, this church will oppress God's people and set up idols so that the saints will serve them. 

11) The Maccabees of the tribe of Judah, outraged by the religious oppression of Antiochus IV, stirred up a popular uprising among the people and fought the Syrians. However, this prophesied about the two witnesses who received the Holy Spirit of Yehoshua who came as a messenger from the tribe of Judah. The two witnesses will fulfill the prophecy of Antiochus IV and fight the appearing church. Just as Maccabees recaptured the Jerusalem Temple in 3 years and 6 months, the two witnesses will build the Temple of Heaven in 3 years and 6 months. 

12) With the popular uprising of Judah Maccabi, Israel drove out the Syrian army and established an independent Hasmonia dynasty. But this prophesied that the kingdom of God would come after the two witnesses. 

In the book of Daniel, there are two little horns that torment God's people. These are Nebuchadnezzar, king of Babylon, and Antiochus IV, king of Syria. Catholicism, mentioned in paragraph 6 above, is the first little horn in the history of spiritual Israel. And paragraph 10, referring to the Antichrist church that will be set up after Catholicism, shows the prophecy of Antiochus IV, who appears as the second little horn. John described the second little horn as a two-horned beast coming up out of the earth.

[Revelation 13:11] I now saw another beast. This one came out of the ground. It had two horns like a lamb, but spoke like a dragon. 

So the two-horned beast that came up out of the earth was a prophecy of the Antichrist Church that would appear and fulfill the prophecy of Antiochus IV. That the beast spoke like a dragon means that Satan, who entered the first beast (Catholicism), entered the second beast. And the Antichrist Church, called the second beast, makes idols for the first beast to worship.

[Revelation 13:13~14] And he performed great and miraculous signs, even causing fire to come down from heaven to earth in full view of men. Because of the signs he was given power to do on behalf of the first beast, he deceived the inhabitants of the earth. He ordered them to set up an image in honor of the beast who was wounded by the sword and yet lived. 

he beast then has people receive the number 666 on their foreheads and hands, symbolizing the beast.. 

[Revelation 13:16~18] And he causes all, the small and the great, and the rich and the poor, and the free men and the slaves, to be given a mark on their right hand or on their forehead, and he provides that no one will be able to buy or to sell, except the one who has the mark, either the name of the beast or the number of his name. Here is wisdom Let him who has understanding calculate the number of the beast, for the number is that of a man; and his number is six hundred and sixty-six. 

The second beast makes an idol for the first beast, and the first beast is Catholicism, which fulfills the prophecy of Babylon. Therefore, if we study Babylon, which is represented by the first beast, we can see the reality of 666.

There are two events in the Bible that represent Nebuchadnezzar, the king of Babylon. The first is a giant statue of God made of gold, silver, bronze, and iron that appeared in the dreams of Nebuchadnezzar, King of Babylon. The giant statue of a god made of gold, silver, bronze, and iron was a prophecy of the great powers that would come after Babylon. When Nebuchadnezzar saw Daniel's ability to interpret dreams, he praised the God of Israel, and to prevent Babylon's destruction, he built a huge statue of gold, which symbolized Babylon, but was the image of the God of Israel that Nebuchadnezzar envisioned.

[Daniel 3:1] Nebuchadnezzar the king made an image of gold, the height of which was sixty cubits and its width six cubits; he set it up on the plain of Dura in the province of Babylon.

King Nebuchadnezzar built a huge golden statue of himself, 60 cubits high and 6 cubits wide, to prevent the destruction of Babylon. But we see that the size of the golden statue is similar to the number of the beasts, 666. So where do we find the other 600? The 600 represents the total amount of gold used to make the golden statue. King Nebuchadnezzar gilded a huge statue of God that was 60 cubits high, and the total amount of gold that went into it was 600 talents. When Solomon built the Temple of God, he used 600 talents of gold to clothe the walls of the Holy of Holies, where God dwells, but the entire length of the Holy of Holies was exactly the same height as the statue Nebuchadnezzar made.

[2 Chronicles 3:8] And he made the most holy house, the length whereof was according to the breadth of the house, twenty cubits, and the breadth thereof twenty cubits: and he overlaid it with fine gold, amounting to six hundred talents. 

Solomon used 600 talents of gold to cover the Most Holy. A talent weighs about 40 kilograms, so you can imagine how much gold went into the Most Holy. But when we looked at the dimensions of the Most Holy, it was 20 cubits wide and 20 cubits long. The Holy of Holies has the shape of a cube of equal length, width, and height. Therefore, the length of the Holy of Holies was 20 cubits wide, 20 cubits long, and 20 cubits high, totaling 60 cubits. The length of the Holy of Holies was equal to the height of the golden image that Nebuchadnezzar had made, and it was 60 cubits long. Therefore, it can be seen that the total amount of gold that went into the golden image and the total amount of gold that went into the Holy of Holies were the same, and 600 talents were used. 

So Satan's number, 666, is not an actual number, but rather a reference to the god image that Nebuchadnezzar created for himself. If you worship the image as God, you will receive the mark of 666. When the second beast in Revelation makes an idol for the first beast, it is prophesying that an idol will be set up and worshiped as God. The fact that the beast coming up out of the earth has two horns indicates that he will set up two idols.

So how do we know the identity of the second beast? We know the identity of the beast if we know the identity of the two idols it sets up, and the beast will set up two idols, God the Father and God the Mother.