The apostle Paul wrote that the day of Christ would not come “unless the falling away comes first, and the man of sin is revealed, the son of perdition, who opposes and exalts himself above all that is called God or that is worshiped, so that he sits as God in the temple of God, showing himself that he is God.” And furthermore, “the mystery of lawlessness is already at work.” (2 Thessalonians 2:3, 4, 7.) Even at that early date the apostle saw errors creeping in that would prepare the way for the papacy. LF 24.1
Little by little, “the mystery of lawlessness” carried on its deceptive work. The customs of heathenism found their way into the Christian church, held back for a time by fierce persecutions under paganism. But as persecution ended, Christianity turned away from the humble simplicity of Christ and adopted the pomp of pagan priests and rulers. The emperor Constantine's professed conversion caused great rejoicing. But now the work of corruption progressed rapidly. Paganism, which seemed to have been conquered, became the conqueror. Its doctrines and superstitions were merged into the faith of those who claimed to be followers of Christ. LF 24.2
This compromise between paganism and Christianity resulted in “the man of sin” that prophecy had foretold. That false religion is a masterpiece of Satan, a monument to his effort to seat himself on the throne to rule the earth according to his will. LF 24.3
It is one of Rome's leading doctrines that God has given the pope supreme authority over bishops and pastors in all the world. More than this, the pope has been called “Lord God the Pope” and declared infallible (see Appendix). The same claim that Satan urged in the wilderness of temptation he still urges through the Church of Rome, and vast numbers give him worship. LF 24.4
But those who reverence God meet the papacy's false claim as Christ met Satan: “You shall worship the Lord your God, and Him only you shall serve” (Luke 4:8). God has never appointed any man head of the church. Papal supremacy is opposed to the Scriptures. The pope can have no power over Christ's church except by claiming it falsely. The Roman Catholic Church charges Protestants with willfully separating from the true church, but she is the one that departed from “the faith which was once for all delivered to the saints” (Jude 3). LF 24.5
Satan knew very well that it was the Holy Scriptures that enabled the Savior to resist his attacks. At every assault, Christ presented the shield of eternal truth, saying, “It is written.” In order for Satan to maintain his control over people and establish the authority of the papal usurper, he must keep them ignorant of the Bible. He must conceal and suppress its sacred truths. For hundreds of years the Roman Church prohibited the circulation of the Bible. The people were forbidden to read it. Priests and leaders interpreted its teachings to support their boastful claims. In this way the pope came to be acknowledged by almost everyone as God's appointed ruler on earth. LF 24.6