Final answer:
Shem and Abraham are both pivotal figures in the Old Testament, known for their commitment to monotheism and their roles in the development of the Abrahamic faiths.
Step-by-step explanation:
The remarkable trait that Shem and Abraham both share in the Old Testament is their direct connection and commitment to monotheism, as well as their significance in the Abrahamic faiths. Shem, as one of the sons of Noah, is often recognized in connection with the lineage that would lead to Abraham. Abraham, on the other hand, is known for his intense commitment to the worship of one God, particularly in the Jewish and Christian traditions, and as a patriarchal figure in Islam. He is central to the narrative that established the worship of one God through a covenant with Yahweh, agreeing to terms of faith and obedience, which included the circumcision of all Hebrew males and in return, the promise of a prosperous land. Both figures are pivotal to the development and continuation of monotheistic belief in the Abrahamic religions: Judaism, Christianity, and Islam.