Why is Israel called the birthplace of Judaism?

Answer 1

Judaism in some form may have existed before the Jews first arrived in Israel, if we are to accept the biblical account, which tells us that the tribes of Israel originated in Mesopotamia, then went to Egypt where they were enslaved, then escaped from Egypt and wound up in Canaan which then became Israel. But Judaism as we know it did originate in Israel. Earlier, pre-Israeli versions of Judaism were very different from what we know as Judaism today. It was originally a polytheistic religion, in which Yahweh, now acclaimed as the one and only God of everything, was originally a storm god, one of many deities in the pantheon.

To add to that thought:

Abraham's son was Isaac. Isaac and his wife,Rebekah, had Jacob.

Jacob, who's name was changed by God to "Israel", had twelve sons, who produced and became the paternal heads of the twelve tribes of Israel....or the "Jews".

Genesis 35:9-29 tells us that the nation of 'Israel' came from the the twelve sons of Jacob, who were born as they passed through Bethel and Bethlehem and other areas. Jacob's son, Joseph, eventually ended up in Egypt, second in command under Pharoah. He invited his family to join him and the twelve tribes grew to a mighty nation under Egyptian rulership, ultimately becoming slaves to the Egyptians. About 400 years later, God brought them (now in the millions)out of Egypt in the "Exodus", parted the Red Sea, eventually crushing the walls of Jericho, and giving them the Promised Land .
So, the literal 'birth place' of Judaism was not really in any one place, though they eventually ended up in the Promised Land which included Jerusalem and that area. (Exodus 19:5)