Abraham, is spoken to by the Lord. He is told that he should leave his country for a different land (Genesis 11:27 - 25:10). Where he would have two children in Canaan, Isaac and Ishmael.
He is later asked by the Lord, as a test of faith, to sacrifice his son, Isaac. This test is stopped at the last minute, when the Lord was convinced that Abraham was truly faithful to Him (Genesis 22).