The Roman Catholic Church contends that its origin is the death, resurrection, and ascension of Jesus Christ in approximately AD 30. The Catholic Church proclaims itself to be the church that Jesus Christ died for, the church that was established and built by the apostles. Is that the true origin of the Catholic Church? On the contrary. Even a cursory reading of the
New Testament will reveal that the Catholic Church does not have its origin in the teachings of Jesus or His apostles. In the New Testament, there is no mention of the papacy, worship/adoration of Mary (or the immaculate conception of Mary, the perpetual virginity of Mary, the assumption of Mary, or Mary as co-redemptrix and mediatrix), petitioning saints in heaven for their prayers, apostolic succession, the ordinances of the church functioning as sacraments, infant baptism, confession of sin to a priest, purgatory, indulgences, or the equal authority of church tradition and Scripture. So, if the origin of the Catholic Church is not in the teachings of Jesus and His apostles, as recorded in the New Testament, what is the true origin of the Catholic Church?
For the first 280 years of Christian history, Christianity was banned by the Roman Empire, and Christians were terribly persecuted. This changed after the “conversion” of the Roman Emperor Constantine. Constantine provided religious toleration with the Edict of Milan in AD 313, effectively lifting the ban on Christianity. Later, in AD 325, Constantine called the Council of Nicea in an attempt to unify Christianity. Constantine envisioned Christianity as a religion that could unite the Roman Empire, which at that time was beginning to fragment and divide. While this may have seemed to be a positive development for the Christian church, the results were anything but positive. Just as Constantine refused to fully embrace the Christian faith, but continued many of his pagan beliefs and practices, so the Christian church that Constantine promoted was a mixture of true Christianity and Roman paganism.
Constantine found that, with the Roman Empire being so vast, expansive, and diverse, not everyone would agree to forsake his or her religious beliefs to embrace Christianity. So, Constantine allowed, and even promoted, the “Christianization” of pagan beliefs. Completely pagan and utterly unbiblical beliefs were given new “Christian” identities. Some clear examples of this are as follows:
(1) The Cult of Isis, an Egyptian mother-goddess religion, was 
absorbed into Christianity by replacing Isis with Mary. Many of the titles that were used for Isis, such as “Queen of Heaven,” “Mother of God,” and theotokos (“God-bearer”) were attached to Mary. Mary was given an exalted role in the Christian faith, far beyond what the Bible ascribes to her, in order to attract Isis worshippers to a faith they would not otherwise embrace. Many temples to Isis were, in fact, converted into temples dedicated to Mary. The first clear hints of Catholic Mariology occur in the writings of Origen, who lived in Alexandria, Egypt, which happened to be the focal point of Isis worship.
(2) Mithraism was a religion in the Roman Empire in the 1st through 5th centuries AD. It was very popular among the Romans, especially among Roman soldiers, and was possibly the religion of several Roman emperors. While Mithraism was never given “official” status in the Roman Empire, it was the de facto official religion until Constantine and succeeding Roman emperors replaced Mithraism with Christianity. One of the key features of Mithraism was a sacrificial meal, which involved eating the flesh and drinking the blood of a bull. Mithras, the god of Mithraism, was “present” in the flesh and blood of the bull, and when consumed, granted salvation to those who partook of the sacrificial meal (this is known as theophagy, the eating of one’s god). Mithraism also had seven “sacraments,” making the similarities between Mithraism and Roman Catholicism too many to ignore. Church leaders after Constantine found an easy substitute for the sacrificial meal of Mithraism in the concept of the Lord’s Supper/Christian communion. Even before Constantine, some early Christians had begun to attach mysticism to the Lord’s Supper, rejecting the biblical concept of a simple and worshipful remembrance of Christ’s death and shed blood. The Romanization of the Lord’s Supper made the transition to a sacrificial consumption of Jesus Christ, now known as the Catholic Mass/Eucharist, complete.
(3) Most Roman emperors (and citizens) were henotheists. A henotheist is one who believes in the existence of many gods, but focuses primarily on one particular god or considers one particular god supreme over the other gods. For example, the Roman god Jupiter was supreme over the Roman pantheon of gods. Roman sailors were often worshippers of Neptune, the god of the oceans. When the Catholic Church absorbed Roman paganism, it simply replaced the pantheon of gods with the saints. Just as the Roman pantheon of gods had a god of love, a god of peace, a god of war, a god of strength, a god of wisdom, etc., so the Catholic Church has a saint who is “in charge” over each of these, and many other categories. Just as many Roman cities had a god specific to the city, so the Catholic Church provided “patron saints” for the cities.
(4) The supremacy of the Roman bishop (the papacy) was created with the support of the Roman emperors. With the city of Rome being the center of government for the Roman Empire, and with the Roman emperors living in Rome, the city of Rome rose to prominence in all facets of life. Constantine and his successors gave their support to the bishop of Rome as the supreme ruler of the church. Of course, it is best for the unity of the Roman Empire that the government and state religion be centralized. While most other bishops (and Christians) resisted the idea of the Roman bishop being supreme, the Roman bishop eventually rose to supremacy, due to the power and influence of the Roman emperors. When the Roman Empire collapsed, the popes took on the title that had previously belonged to the Roman emperors—Pontifex Maximus.
Many more examples could be given. These four should suffice in demonstrating the origin of the Catholic Church. Of course, the Roman Catholic Church denies the pagan origin of its beliefs and practices. The Catholic Church disguises its pagan beliefs under layers of complicated theology and “church tradition.” Recognizing that many of its beliefs and practices are utterly foreign to Scripture, the Catholic Church is forced to deny the authority and sufficiency of Scripture.
The origin of the Catholic Church is the tragic compromise of Christianity with the pagan religions that surrounded it. Instead of proclaiming the gospel and converting the pagans, the Catholic Church “Christianized” the pagan religions, and “paganized” Christianity. By blurring the differences and erasing the distinctions, yes, the Catholic Church made itself attractive to the people of the Roman Empire. One result was the Catholic Church becoming the supreme religion in the Roman world for centuries. However, another result was the most dominant form of Christianity apostatizing from the true gospel of Jesus Christ and the true proclamation of God’s Word.
Second Timothy 4:3–4 declares, “For the time will come when men will not put up with sound doctrine. Instead, to suit their own desires, they will gather around them a great number of teachers to say what their itching ears want to hear. They will turn their ears away from the truth and turn aside to myths.”
