Marcion of Sinope (; Greek: Μαρκίων Σινώπης; c. 85 – c. 160) was an important leader in early Christianity. His theology rejected the deity described in the Hebrew Scriptures and in distinction affirmed the Father of Christ as the true God. The Church Fathers denounced Marcion, and he chose to separate himself from the proto-orthodox church. He is often considered a catalyst in the development of the New Testament canon.