In second century Rome a debate arose as to whether Christianity should abandon its Jewish roots. One group were known as the "Ebionites" the name of which derives from the Hebrew word for "Poor" and was originally applied to them because they were from the lower social groups. Ebionites echoed Jewish ideas at a number of points particularly with regard to the identity of Jesus Christ, often describing him as the new Elijah.
In the middle of the second century Marcion of Sinope AD 110-60 a wealthy Roman Christian advocated the opposite approach because Christianity had gained a significant following in the capital of Rome. Marcion wanted to bring about a fundamental change in the way the church positioned itself in relation to Judaism, to sever links and have nothing to do with its God, beliefs or rituals. The old testament God was a war God who he believed had nothing to do with the Christian God.
This would have represented a radical break with the established traditions of the new church and would have meant a rewriting of the early letters and doctrine. The majority position was that the new teaching through Christ were a fulfillment of the promise that God had made to Abraham, Isaac and Jacob which had been disclosed through the law and the prophets. Marcion in contrast wanted Christianity to be a new distinct faith arguing that it was not the same God. The old God was seen as inferior and defective whilst the Jesus of the gospel was really good news. He proposed that Jesus had no direct relation to the Jewish creation God, that he should not be seen as the Messiah but rather sent by a previously unknown God who was characterised by Love rather than jealously or aggression. The old God he said created evil things, delighted in wars, was fickle and inconsistent, the two Gods were not equal as one was a stern and warlike judge and the other mild, gentle, kind and good.
Most of the documents widely accepted as authoritative by the early Christians made extensive reference to the Jewish scriptures. These were later to form the basic canon for the New Testament. Marcion however developed his own canon of Christian documents which excluded all Jewish references. Matthews gospel was excluded altogether as it was sympathetic toward Judaism, he even edited ten of Paul's letters along with the gospel of Luke removing the annunciation, the nativity, Christs baptism and temptation.
The Church reflected on and considered Marcions view but decided that the hope in Christ was for Jews as well as gentiles. Justin Martyr was adamant that the story of Jesus could not be told in isolation from its Jewish roots. It was vital to understand how they related and fitted together including the creation story and Gods calling of Israel but also revealing Jesus as a means of achieving the age old human quest for understanding, meaning and significance. Jesus is the focal point from which the old testament stories should be seen.
Summary and references from Christian history - An Introduction by Alister E McGrath