Roman Catholicism was instituted in A.D. 380 by Roman Emperor Theodosius I as a way to destroy Christianity. Before that, Rome had tried unsuccessfully to stamp out Christianity in defense of government power over the people and to protect its pagan traditions by lining up crucified Christians all along its highways, feeding them to lions, seizing their property, and imprisoning them to work in underground mines for the rest of their lives. That wasn't working, people continued to become Christians. Therefore, Rome declared "Christianity" the state religion but only pardoned Christians who swore allegiance to Rome, and confessed belief in the newly-created doctrine of the Trinity under the Nicene Creed.
Those who believed Jesus and God the Father were separate entities, and that Jesus was the first-born of creation (a created being rather than eternal, according to Colossians 1:15 and Revelation 3:14) were declared Arians and exterminated. This was only the beginning of Catholic persecutions of "heretics". Next were the Novatians and Donatists, who both believed in re-baptizing rather than infant baptism. They too were declared heretics and slaughtered.
I believe Catholicism was Satan's attempt to persecute real Christianity while removing popular appeal by creating a fake Christianity. This allowed Rome to continue persecuting the real Christians, giving itself justification for doing so (since now they were "heretics" rather than "Christians"), allowed it to preserve its pagan traditions under the guise of "Christianity", allowed it to attack all forms of real Christianity as heretical, eliminating them wherever they'd sprout, and allowed it to retain power over government and the people (confession could be considered a population control tactic, e.g.).
Christian Groups Persecuted by Catholicism
There were actually numerous groups persecuted by Catholicism as heretics long before the Reformation, a little-known fact, as seen from the "Trail of Blood" chart by J.M. Carroll, including Montanists, Novatians, Puritans (no relation to 17th century group), Cathar, Donatists, Paulicians, Henricians, Arnoldists, Albigenses, and Waldenses.
A.D. 150-800. Believed God continued giving revelation to the Church. They were the first to call the Holy Spirit God. They emphasized fasting and rejected remarriage after divorce, consistent with Jesus' teachings (Matthew 5:32) but angering Catholicism. Tertullian defended them. 
A.D. 254-600. Denied readmission of Christians who denied their faith and sacrificed to pagan deities. They also said remarriage was wrong after divorce. For this they were considered heretics and stamped out. According to Catholic sources, they also held similar beliefs to the Arians in considering Jesus created and subject to God the Father. They called themselves Puritans (no relation to later group in 16th century). 
A.D. 311-750. Considered Roman Catholicism the "Church of Judas'. Like the Novatians, they said those who had denied the Christian faith under persecution should not be re-admitted, and were traitors. They rejected infant baptism, and thus practiced rebaptism, a serious crime by Catholicism's standards.
A.D. 320-671. Claimed Jesus was created and separate from God the Father. Catholicism instituted the Nicene Creed declaring a Trinity and that Christ was eternal and born of a virgin, in response. Their books were burned, they were killed, and much of what we know about them is written by their enemies. Judaism views them somewhat favorably because they did not seek to persecute Jews when in power.
A.D. 650-950. They rejected worship of Mary, saints, the cross, and Mass, and believed everyone should be able to freely study the Bible for themselves. Like many others they were accused of Dualism, considering a good God vs. an evil one of the world, and opposition to the materialism Catholicism worshiped.
A.D. 800-Present. They created a non-Latin translation of the Bible, enraging the Catholic Church, who spent centuries trying to massacre them out of existence. They emphasized poverty and rejected Indulgences, Purgatory, prayer for the dead, popes, holy water, refused to take oaths, and considered Roman Catholicism the Harlot of Babylon.
A.D. 950-1900. Dualists, rejected worship of the cross and emphasis on external church buildings.
A.D. 1100 - Present. Also called Paterines. Believed in Dualism, that the God of the Bible is opposed by a god of this world, Satan (Biblical - 2 Corinthians 4:4, John 12:31, 16:11). They believed in poverty, rejected priesthood and church buildings, and refused to swear oaths (Biblical - see Matthew 5:34, James 5:12). Despite the Albigensian Crusade, which killed some 500,000 of them, remnants have survived to the present day.
A.D. 1100-1350. Believed in Dualism, a good God vs. an evil one of this world, Satan, and condemned Catholic "corruption, ritualistic pomp, and superficiality". While they disagreed with Judaism, they coexisted peacefully. Were destroyed in one of the bloodiest massacres in Catholic history, the Albigensian Crusades.
A.D. 1100-1250. Also called Henricians. Rejected an outward visible church, said the real church was in the hearts of all believers. Rejected infant baptism, crucifix worship, prayer to the dead, and Mass/the Eucharist.
A.D. 1136-1200: Founded by Arnold of Brescia. Rejected infant baptism and material possessions.
The following is an examination of Catholic doctrines:
- Virgin Birth and Priestly Celibacy
- Good Friday
- Church Foundation
- Papal Authority
- Infant Baptism
- Judas Forgiveness
The most explicit reference to Roman Catholicism is found in Revelation chapters 17-18 which discuss a "great city" which would fall away from God, persecute Christians across all ages, and ultimately be destroyed by God at the last. The city's name? Babylon, what the early Christian Church called Rome.
If there's any doubt, it is specifically said to be a great city in 17:18 ("And the woman which thou sawest is that great city, which reigneth over the kings of the earth.") built on 7 mountains as specified in 17:9. ("And here is the mind which hath wisdom. The seven heads are seven mountains, on which the woman sitteth.") Rome of course is worldwide recognized for "The Seven Hills of Rome". It is symbolized by a great whore with fancy clothing, a cup full of abominations, and on whose forehead is written, "Mystery: Babylon The Great - The Mother of Harlots and Abominations of the Earth". (17:1-6)
Other features of Babylon mentioned are:
- Drunk with the blood of saints, martyrs of Jesus, prophets, and all those slain upon the earth. (17:6; 18:20,24)
- Rules over peoples, multitudes, nations, and languages. (17:15; 18:3) By its sorceries were all nations deceived. (18:23) Rules over the kings of the earth. (17:2,18; 18:3,9)
- Out of it will come the Beast, more commonly called the Antichrist, which will be worshiped by all non-Christians on the earth in the final world empire. (17:8) The Beast will be the 8th in a lineage (kings?) and ten previously kingdomless kings will receive power as kings under the Beast, to serve him, only to be destroyed by the returning Christ. (17:9-14)
- It is a great merchant city by the sea to be mourned by merchants and shipmasters for their loss of trade in gold, silver, jewels, pearls, clothing, thyine wood, ivory, bronze, iron, marble, spices, ointments, wine, oil, flour, wheat, cattle, chariots, slaves, and souls of men. (18:3,11-19)
- Said to be the home of devils, foul spirits, and cage to every unclean and hateful bird. (18:2)
- Christians are a part of it, and commanded to "Come out of her, my people, that ye be not partakers of her sins, and that ye receive not of her plagues, for her sins have reached unto heaven, and God hath remembered her iniquities." (18:4-5)
- Known for its harpers and musicians, including pipers and trumpeters, as well as for its craftsmen. (18:22)
- To be utterly destroyed with death, mourning, and famine; burned by fire (which Rome was in A.D. 64) and no more found at all. (17:16; 18:8,21)
In all my years of examining Catholic doctrines, I'm not sure I've found a single one yet that actually comes even close to teaching what the Bible does. Not one.