Contrasting the “Old Testament” God and “New Testament” God is all too often an approach taken in comparing the two theologies. I was taught, at a Catholic high school actually, that his was not the right approach to take in comparing Jewish and Christian theologies.
What I did not know was that this type of thinking was at the root of an early heresy- the one associated with Marcion. He taught that the God worshipped by the Israelites in the Old Testament was different from the God revealed to the world in the New Testament.
I am not myself a theologian, but what I had come to understand from high school “theology class,” is that the apparent contrast between one part of the scripture and the other is better viewed as a function of the different contexts in which those texts were written then as a function of two different faiths. Normative Christian beliefs are of course different from the traditional tenants of Normative Judaism, but every time I hear from experts who study these differences, I am surprised to find how similar the two are.
In this case, I was surprised to learn how strongly portions of the New Testament itself seems to be at odds with the early heresy that attempted to create this distinction.