Did Abraham follow the Sabean religion?

Answer 1

Even in Ur, the one true God called Abraham to come out and leave the idolatry of Ur. Thus, it seems from an early part of his life, Abraham had an awareness of the one true God, or at the vert least was somewhat separated from a total commitment to the moon God, such that almighty God was able to call him out and he was willing to go.

Throughout scripture Abraham is known as a man of faith, referring to his dedication to the one true God of The Bible and not just faith for its own sake or faith in general. If Abraham had been a follower of the Sabean religion, then there would have to have been a time when he forsook this and separated himself to seek the one true God. It is certainly possible that this happenned, but this would be only conjecture with no documented support, but there is plenty of documented support for him being a faithful believer in the God of the Bible from start to end.

Answer 2

There seem to be at least three distinct and unrelated Middle Eastern ethnic/religious groups that use the name Sabean, Sabaean or Sabian.
One group, the Harranians, later to be known as the Sabaeans, would at least have been in the right geographical location, but it is a moot point whether their religion, or a recognisable early version of it, existed at the time attributed to Abraham. From biblical and archaeological evidence, we can say that the dominant worship in Harran at that time was dedicated to the moon god.

Answer 3

No. As a child , Abraham rejected idolatry and polytheism while still living in Babylonia (footnote 1, below), before he came anywhere near the Sabeans. See also:

Biography of Abraham

Footnote 1:

An excerpt from Maimonides' Mishneh Torah (Hilchot Avodat Kochavim 1:2-3):

"...As the years passed, God's glorious and awesome name was forgotten by the entire population. It was no longer part of their speech or thought, and they no longer knew Him....

The world continued in this fashion until the pillar of the world, Abraham, was born.

As Abraham grew, he began to explore in his mind, day and night, wondering: How is it possible for the spheres to revolve without having anyone controlling them? Who is causing them to revolve? Surely, they do not cause themselves to revolve.
He had no teacher, nor was there anyone to inform him. He was mired in Ur Kasdim among the foolish idolaters. His father, mother, and all the people were idol worshipers. However, his heart was exploring and gaining understanding.
Ultimately, he comprehended the way of truth and understood the path of righteousness through his careful contemplation. He realized that there is One God who controls the spheres and who created everything; and there is no other god among all the other entities. He realized that the entire world was making a mistake. What caused them to err was their service of the stars and images, which had made them lose awareness of the truth.
When Abraham came to recognize and know God, he began to formulate replies to the inhabitants of Ur Kasdim and debate with them..."