In the Old Testament tradition Abraham represents a founding figure, from which the promise of the land and of the progeny is developed (particular dimension); at the same time he and with him also his progeny mediates blessing for all the nations (universal dimension). This is connected with the understanding of the role of the Jews as the chosen nation for the rest of the world.
For the New Testament authors, the figure of Abraham plays a significant role, too. A specifically understood Abraham tradition appears in the New Testament especially by Paul in the letter to Romans and Galatians, further in the letter to the Jews, and in the letter of James.
Apostle Paul emphasises the universal dimension of Abraham and uses his faith as a principle of legitimating. In this way he transfers Abraham or, better to say, promises given to him through Christ to Christians, esp. pagan-Christians.
He deals with the Jewish tradition in the texts where he mentions Abraham in a highly selective way and quite freely, we may even say in contradiction with the tradition which he must have known. He does not bring an accommodated Abraham tradition but its new interpretation.