The error of Marcionism is seen in its assertion that there are two different God observed in the Old and New Testaments. The first, vengeful, full of wrath and evil. The later, a God of love and forgiveness. Of course the obvious problem in this view is the originator of this heresy, Marcion of Sinope, does not understand the purpose of the Old Testament as a foreshadow of what would be fulfilled in the New Testament. God’s wrath agains sin, the required sacrifices, judgement for violations of God’s law; all designed to give the reader a view into the mind of God concerning sin and salvation.
The wrath against sin is a preview of the future judgement that all human beings are approaching. The sacrifices, a picture of the blood that must be shed in order to atone for sins. The judgment, a present position and plight of people in their helpless condition.
As Jesus comes as the Lamb of God who takes away the sins of the world, His death on the cross and the blood that He poured out for sins, as the payment necessary to forgive all sins.
One common denominator that is becomes visible in all Christian heresies is their similarity to Gnosticism. In every case of heresy, the person who created the abhorrent view of Christ and His salvation, simply did not understand the text of the Bible.
Marcion believed the Gnostic idea of lesser gods who rule the world, while the true God is inaccessible to man. He accepted only eleven books of the Bible; an abridged gospel of Luke, Romans, 1 Corinthians, 2 Corinthians, Galatians, Ephesians, Philippians, Colossians, 1 Thessalonians, 2 Thessalonians, and Philemon. The reason, the others did not fit his bias for the two god assertion.
The early Christian church excommunicated Marcion in 144 A.D., due to his non traditional view of God and the scriptures.
Marcion establish a church in Rome which taught his strange doctrines and views of God. After four hundred years this teaching became unacceptable as people began to read the Bible for themselves.
- Marcion asserted a disjunction between the God of wrath from the Old Testament and the God of Love in the New. Marcion stated that Jesus was God but never became human. According to Marcion, Judaism is no longer necessary and in replacement theology, Christianity is preeminent.
- In Marcion philosophy, the two gods of the Old and New Testaments are not equal;
- “Thus far our discussion seems to imply that Marcion makes his two gods equal; one judgmental and mighty in war; the New Testament god is gentle, and good, far superior.
- In “Against Heresies, 1.72.2, Irenaeus writes: “Besides this, Marcion mutilates the Gospel which is according to Luke, removing all that is written respecting the generation of the Lord, and setting aside a great deal of the teaching of the Lord, in which the Lord is recorded as most clearly confessing that the Maker of this universe is His Father.”
- Author James Eckman writes concerning Marcion: “He argued that there were two gods—a creator and a redeemer. The former was the god of the Old Testament, who was evil and capricious. The latter was the god of love and redemption, whom Jesus Christ revealed.”
 Donald K. McKim, “The Westminster Dictionary of Theological Terms,” Second Edition: Revised and Expanded.
 Alexander Roberts, James Donaldson, and A. Cleveland Coxe, “Tertullian, Against Marcion,” “Latin Christianity:” Its Founder, Tertullian. vol. # 3, The Ante-Nicene Fathers, Buffalo, New York: Christian Literature Company from 1885.
 W. A Elwell and P. W Comfort, 2001, Tyndale Bible Dictionary. Tyndale reference library, 855. Wheaton, Illinois, Tyndale House Publishers.
 James P Eckman, “Exploring Church History,” Wheaton, Illinois, Crossway, 2002.