Marcion was a wealthy second-century Roman who studied Jewish scripture and compared it to the teachings of Christ. He maintained that the teachings of Christ were incompatible with that of the Old Testament. He believed that Jesus is the Messiah and that Paul is Jesus’ chief apostle. However, Marcion denied the humanity of Christ and held that He is not the God of the Old Testament. Marcion claimed that the God of the Old Testament is a demiurge, an evil being, who is separate and lower than the God of the New Testament. Marcion saw God in the New Testament portrayed as loving and forgiving, very unlike the God of the Old Testament, who Marcion viewed as jealous, wrathful, and genocidal. He taught that the demiurge created a world filled with suffering and imperfection. This, Marcion maintained, is not the true God. Furthermore, since the Old Testament God is the God of the Hebrews, Marcion maintained that any association with the Hebrew religion is evil.
Regarding Christ’s work in salvation, Marcion claimed that Christ was not sent to save the Jews, but to bring salvation from the demiurge and to make known the truth of the good God, who may not have even been known by the demiurge. He claimed that those who were loyal to the demiurge crucified Christ.
Marcion developed a canon, which included an edited version of Luke, called “Gospel of Christ”. His canon did not include any of the Old Testament, nor did it include certain parts of the New Testament such as the prophecies of Christ, His birth, His baptism, and His death. Marcion wanted to show that Christ was revealed as a man, but was not really a man. Thus, he eliminated parts of Scripture that attest to Christ’s humanity.
Marcion’s teachings brought division in the early church. For the first time in the post-apostolic period, the church was led to formulate creeds in order to defend itself from these and other heresies. This also led to the adoption of the current canon of the New Testament.
Marcion was also a legalist who imposed strict laws upon his followers. He believed in a strict moral structure and prohibited sex of any sort, even between married couples.
Marcion was a heretic who did not believe in the inerrant, authoritative Word of God. He, just like many other heretics before and after him, chose which parts of Scripture to believe and which ones to deny. He claimed that Christ’s teachings contradict the Old Testament, but any knowledgeable reader of Scripture would know what Christ really said about the Old Testament. Jesus quoted Old Testament Scripture numerous times and accused the Jewish religious leaders of abusing the law. He even said that He did not come to destroy, contradict, or even revise the law, but that He came to fulfill the law (Matthew 5:17-18). Jesus spoke of the Old Testament often. He lived His life according to the law.
The humanity of Christ is also clearly presented in Scripture. Two of the most notable references are John 1, in which Christ is presented as the eternal Word which took on flesh, and Hebrews 4:14-16, which presents Christ as the Great High Priest Who is able to sympathize with His people.
The claim that the Old Testament God is a demiurge is nothing new. Marcion takes this belief from the Gnostics. Marcion cannot truly comprehend the justice and righteousness of God (Who can?) so he asserts that God is evil because he judges humans for their sins.
The majority of Marcionist teaching is based on human reasoning. Marcion struggled with the answers to difficult and confusing questions, such as how a just God can sentence people to death, or how a good God would allow evil to occur. His questions were unlike questions that are currently being asked in post-modern evangelicalism. They are legitimate questions. But Marcion was not satisfied by the answers he found in Scripture, so he sought to form his own conclusions apart from Scripture and based on conjecture and reasoning. This is the problem that occurs when we stray from Biblical teaching. Scripture teaches that man is totally depraved and unable to find the answers to life’s difficult questions on his own (Jeremiah 17:9). Therefore we cannot find truth outside of Christ and His inspired, infallible, and authoritative Word.