You probably know this. This is an account of his believing. He believed and was saved long before this.
Acts 7:2
And he said, “Brethren and fathers, listen: The God of glory appeared to our father Abraham when he was in
Mesopotamia, before he dwelt in Haran,
27Now these are
the records of the generations of Terah. Terah fathered Abram, Nahor, and Haran; and Haran fathered Lot.
28Haran died
[n]during the lifetime of his father Terah in the land of his birth, in Ur of the Chaldeans.
29Abram and Nahor took wives for themselves. The name of Abram’s wife was Sarai, and the name of Nahor’s wife was Milcah, the daughter of Haran, the father of Milcah
[o]and Iscah.
30Sarai was unable to conceive; she did not have a child.
31Now Terah took his son Abram, and Lot the son of Haran, his grandson, and his daughter-in-law Sarai, his son Abram’s wife, and they departed
[p]together from Ur of the Chaldeans to go to the land of Canaan; and they went as far as Haran and
[q]settled there.
32The days of Terah were 205 years; and Terah died in Haran.
The Lord had already appeared to Abram, before he left Ur, Mesopotamia............Faith alone in Christ alone.