There are many historical contradictions within Roman Catholicism between Papal decrees and other Papal decrees, Papal decrees and Ecumenical Councils, and Ecumenical Councils with other Ecumenical Councils.
For example, observe Pope Paul IV (1476-1559 AD) say that the Jews are "condemned to eternal slavery", says that they have "invaded Rome", and laments that they do not wear identifying garments so as to stand out from Christians:
Pope Paul IV - Cum Nimis Absurdum (1555 AD)
Since it is completely senseless and inappropriate to be in a situation where Christian piety allows the Jews (whose guilt - all of their own doing - has condemned them to eternal slavery) access to our society and even to live among us; indeed, they are without gratitude to Christians, as, instead of thanks for gracious treatment, they return invective, and among themselves, instead of the slavery, which they deserve, they manage to claim superiority: we, who recently learned that these very Jews have insolently invaded Rome from a number of the Papal States, territories and domains, to the extent that not only have they mingled with Christians (even when close to their churches) and wearing no identifying garments, but to dwell in homes, indeed, even in the more noble [dwellings] of the states, territories and domains in which they lingered, conducting business from their houses and in the streets and dealing in real estate; they even have nurses and housemaids and other Christians as hired servants.
Then, observe the Second Vatican Council (1962-1965 AD) denounce "displays of anti-Semitism, directed against Jews at any time and by anyone":
Vatican 2 (1965 AD) - Nostra Aetate
4 Furthermore, in her rejection of every persecution against any man, the Church, mindful of the patrimony she shares with the Jews and moved not by political reasons but by the Gospel's spiritual love, decries hatred, persecutions, displays of anti-Semitism, directed against Jews at any time and by anyone.
5 The Church reproves, as foreign to the mind of Christ, any discrimination against men or harassment of them because of their race, color, condition of life, or religion.
Or, observe Pope Innocent IV (1195-1254 AD) demand the torture of heretics in order to extract confessions, and Pope Leo X (1475-1521 AD) defend burning heretics at the stake:
Pope Innocent IV - Ad Extirpanda (1252 AD)
25 The head of state or ruler must force all the heretics whom he has in custody, provided he does so without killing them or breaking their arms or legs, as actual robbers and murderers of souls and thieves of the sacraments of God and Christian faith, to confess their errors and accuse other heretics whom they know, and specify their motives, and those whom they have seduced, and those who have lodged them and defended them, as thieves and robbers of material goods are made to accuse their accomplices and confess the crimes they have committed.
Pope Leo X - Exsurge Domine (1520 AD)
33 That heretics be burned is against the will of the Spirit. (Condemned)
Then, observe the Second Vatican Council (1962-1965 AD) repudiate the use of force in religious matters, and extol religious freedom as a fundamental human right, given by God:
Vatican 2 (1965 AD) - Dignitatus Humanae
2 This Vatican Council declares that the human person has a right to religious freedom. This freedom means that all men are to be immune from coercion on the part of individuals or of social groups and of any human power, in such wise that no one is to be forced to act in a manner contrary to his own beliefs, whether privately or publicly, whether alone or in association with others, within due limits.
The council further declares that the right to religious freedom has its foundation in the very dignity of the human person as this dignity is known through the revealed word of God and by reason itself. This right of the human person to religious freedom is to be recognized in the constitutional law whereby society is governed and thus it is to become a civil right.
3 Wherefore every man has the duty, and therefore the right, to seek the truth in matters religious in order that he may with prudence form for himself right and true judgments of conscience, under use of all suitable means. On his part, man perceives and acknowledges the imperatives of the divine law through the mediation of conscience. In all his activity a man is bound to follow his conscience in order that he may come to God, the end and purpose of life. It follows that he is not to be forced to act in a manner contrary to his conscience. Nor, on the other hand, is he to be restrained from acting in accordance with his conscience, especially in matters religious.
The above examples could be multiplied. The following are articles covering similar contradictions within historical Roman Catholicism:
These examples disprove the Roman Catholic assertion that their Church is the infallible teacher of all Christians. Rather, it is a fallible institution, which merely makes bold claims which do not withstand the test of historical scrutiny:
Pope Gregory VII - Dictatus Papae (1090 AD)
22 The Roman church has never erred; nor will it err to all eternity, the Scripture bearing witness
The two most recent dogmas to be infallibly defined by the Pope were both in relation to Mary:
According to the Roman Catholic Church, both of these dogmas are required to be believed by all Christians. If one rejects the Immaculate Conception, they are "separated from the unity of the Church" (Ineffabilis Deus, 1854 AD). If one rejects the Assumption, they "will incur the wrath of Almighty God and of the Blessed Apostles Peter and Paul" (Munificentissimus Deus, 1950 AD).
Beginning with the Immaculate Conception - covered in its own article here - this doctrine was explicitly rejected by five Saints, four of whom are also Doctors of the Church:
Notice that even late into the 13th century, the most prominent Catholic writer of the last 1,000 years, Thomas Aquinas, explicitly rejected the doctrine as "derogatory to the dignity of Christ" (Summa Theologica, Part 3, Question 27, Article 2). Yet, in 1854, Pope Pius IX (1792-1878 AD) made it a required belief for Salvation.
Biblically speaking, Mary was a sinner. God explicitly recorded her making a "sin offering" for an "atonement for her" in the text of the New Testament (Luke 2:24, Leviticus 12:6-8), without inspiring Luke to give any indication whatsoever that this was somehow unnecessary, or not for all the purposes that it was said to be for in the Law.
The Assumption of Mary - covered in its own article here - has an even worse historical record than the Immaculate Conception. It is entirely absent from the existing writings of the Ante-Nicene (pre-325 AD) Christian writers, many of whom spoke about Mary at length. It does not make sense for such a momentous event, if it actually happened, to be altogether absent from Scripture, as well as the writings of the early Church.
Further, in a work by Epiphanius (310-403 AD) in which Mary is mentioned hundreds of times, not only does he never mention the Assumption, but he explicitly says that "No one knows her end", after speculating on what happened to her:
Epiphanius (310-403 AD) - The Panarion, Antidicomarians 23
8 And there have been many such things to mislead the deluded, though the saints are not responsible for anyone's stumbling; the human mind finds no rest, but is perverted to evils. The holy virgin may have died and been buried - her falling asleep was with honor, her death in purity, her crown in virginity. Or she may have been put to death - as the scripture says, "And a sword shall pierce through her soul" - her fame is among the martyrs and her holy body, by which light rose on the world, [rests] amid blessings. Or she may have remained alive, for God is not incapable of doing whatever he wills. No one knows her end.
Therefore, not only are these doctrines found nowhere in Scripture, but they are also ahistorical, either lacking historical attestation, or even being explicitly repudiated by those whom the Catholic Church views as authoritative teachers.
These dogmas are also part of a broader stream of Mariolatry - excessive exaltation of Mary - that abounds in Roman Catholicism, which is extensively documented in this article. Also see the aforementioned articles for a much more thorough presentation of the problems involved with each Marian dogma, including quotations from the early Christian writers mentioned above.
The concept of the Papacy has no Biblical support. Peter does not act as a Pope, none of the Apostles refer to a Papacy, or needing to submit to Peter or Rome, and even up to the very end of Christ's ministry, the Apostles were disagreeing amongst themselves as to who would be the greatest (Luke 22:24-30).
In Galatians 2:11-14, Paul directly and publicly rebukes Peter for his errant behavior at Antioch. At the Council of Jerusalem in Acts 15, it is James, not Peter, who delivers the final judgment (Acts 15:19-23), and the letter containing the judgement is written, not in the name of Peter, but in the name of the "apostles and elders and brethren" (Acts 15:23).
The three most common Roman Catholic prooftexts for the Papacy do not, in context, teach anything resembling the modern concept of the Papacy:
Because the Roman Catholic interpretation of Matthew 16 is so vital to the doctrine of the Papacy, it is worth noting that historically, the prevailing view of the "rock" of Matthew 16:18, as discussed above, was that it indeed refers to Peter's confession that Jesus was the Messiah:
James White - The Roman Catholic Controversy - Chapter 8, pg. 120
The French Roman Catholic Launoy (1603-1678 AD) surveyed the patristic evidence and found seventeen citations supporting the concept that Peter is the rock of Matthew 16. Please note that this does not mean that all sixteen of these Fathers also felt that this meant that the bishop of Rome was a Pope, but only that they saw Matthew 16 and the phrase "this rock" as referring to Peter. However, Launoy found sixteen citations that identified the rock as Christ. He found eight that identified all the Apostles together as forming the rock of Matthew 16. And he found forty-four citations indicating that the rock of Matthew 16 was the confession of faith made by Peter in Jesus Christ.
If we add these numbers together, we find that the Roman Catholic position, which claims to have always been the faith of the Catholic Church, in Launoy's survey actually represents twenty percent of the Fathers (17/85). Eighty percent of the time, then, the early Fathers expressed, in Vatican I's words, "perverse" opinions at the very best. I might note that even as late as the Council of Trent it was said this passage was referring to the faith that Peter expressed.
In addition to the lack of Biblical evidence, many facts of history repudiate the modern Roman Catholic concept of the Papacy, wherein the Church has supposedly recognized the Bishop of Rome as having universal jurisdiction and ultimate authority, or being the rock upon which the Church stands:
The Catholic Canon of Scripture, defined infallibly at the Council of Trent (1545-1563 AD), differs from the Protestant and Jewish Bible in the Old Testament with the addition of the following books:
None of the above books are quoted as Scripture in the New Testament. Further, the canon of the Jews at the time of Christ, as attested to by the first-century Jewish witness Josephus (37-100 AD), excludes these apocryphal books:
Josephus (37-100 AD) - Against Apion - Book 1
8 For we have not an innumerable multitude of books among us, disagreeing from and contradicting one another, [as the Greeks have,] but only twenty-two books, which contain the records of all the past times; which are justly believed to be divine; and of them five belong to Moses, which contain his laws and the traditions of the origin of mankind till his death. This interval of time was little short of three thousand years; but as to the time from the death of Moses till the reign of Artaxerxes king of Persia, who reigned after Xerxes, the prophets, who were after Moses, wrote down what was done in their times in thirteen books. The remaining four books contain hymns to God, and precepts for the conduct of human life.
It is true, our history hath been written since Artaxerxes very particularly, but hath not been esteemed of the like authority with the former by our forefathers, because there hath not been an exact succession of prophets since that time; and how firmly we have given credit to these books of our own nation is evident by what we do; for during so many ages as have already passed, no one has been so bold as either to add any thing to them, to take any thing from them, or to make any change in them; but it is become natural to all Jews immediately, and from their very birth, to esteem these books to contain Divine doctrines, and to persist in them, and, if occasion be willingly to die for them.
Above, Josephus enumerates 22 books, which are the same 39 books of the Protestant Old Testament, grouped according to Jewish tradition. This is significant, because before the New Testament Church, the Jews were the people of God, who were entrusted with the writings of the prophets (Romans 3:1-2). And, their canon excluded the Roman Catholic Apocrypha.
Consequently, as can be viewed on this site, for instance, many early Christian writers excluded these books when enumerating the Canon of Scripture:
The above list represents 10 Saints, 8 of whom are Doctors of the Church, who did not recognize some or all of the Catholic canon. Yet, in the 16th century, the fourth session of the Council of Trent anathematized all who reject the Apocrypha as inspired.
This topic is discussed further in its own article here, which includes many more early Jewish sources, as well as potential problems with the content of the apocryphal books themselves.
In addition to all that has been discussed above, the Roman Catholic Church has departed in many other ways from the teaching of the early Church and the Apostles.
The following are five unbiblical doctrines or practices of the Roman Catholic Church, and the verses of Scripture which refute them:
For more than 20 additional examples, see this article.
The Roman Catholic Church is a false denomination of Christianity. It does not withstand Biblical or historical scrutiny, and has often perpetrated horrible things against those who disagreed with it on matters of doctrine, making their errors and relentless condemnations of all other Christians even more egregious, in spite of their modern hypocritical attempts to appear ecumenical:
Pope Boniface VIII - Unam Sanctam (1302 AD)
Urged by faith, we are obliged to believe and to maintain that the Church is one, holy, catholic, and also apostolic. We believe in her firmly and we confess with simplicity that outside of her there is neither salvation nor the remission of sins
Therefore, if the Greeks or others should say that they are not confided to Peter and to his successors, they must confess not being the sheep of Christ, since Our Lord says in John "there is one sheepfold and one shepherd."
Furthermore, we declare, we proclaim, we define that it is absolutely necessary for salvation that every human creature be subject to the Roman Pontiff.