Satsuma makes a good point about "Abrahamic". It is a term with anthropological value and one that I see bandied about in secular society, but when I became religious one of the things that struck me was how little value classical Christian thought assigns to someone being Jewish or Muslim, and so forth. If you were to ask me whether Christianity is more similar to Islam or Buddhism, I would answer the question based on the theology, cosmology, and phronema of these systems. That Christianity and Islam both credit Abraham as a major forebear is essentially irrelevant in the calculus.
I hadn't really thought about this before. The "Abrahamic" category makes obvious sense from an outside perspective, and it makes perfect sense from an Islamic perspective, being basically an Islamic concept. It does not clearly make a lot of sense from a Christian perspective. I think it does make some sense from a Jewish perspective, considering the concept of the Abrahamic covenant, but then again Christians by and large do not practice circumcision so maybe the only Abrahamic religions are Judaism and Islam.
Abraham was too important in the writing of Paul for Christianity to not be considered an Abrahamic religion. What’s more, the history of Christianity itself follows a biblical model in that it’s an example of the younger son (Christians) usurping the elder (Jews). Though I know Muslims have a different view of the Isaac and Ishmael story than Christians and Jews do.