Abraham’s legacy was that we can become friends with God and children of God.

Genesis 25:1-11
Abraham’s Death and His Descendants
25 Abraham took another wife, whose name was Keturah. 2 She bore him Zimran, Jokshan, Medan, Midian, Ishbak, and Shuah. 3 Jokshan fathered Sheba and Dedan. The sons of Dedan were Asshurim, Letushim, and Leummim. 4 The sons of Midian were Ephah, Epher, Hanoch, Abida, and Eldaah. All these were the children of Keturah. 5 Abraham gave all he had to Isaac. 6 But to the sons of his concubines Abraham gave gifts, and while he was still living he sent them away from his son Isaac, eastward to the east country.

7 These are the days of the years of Abraham’s life, 175 years. 8 Abraham breathed his last and died in a good old age, an old man and full of years, and was gathered to his people. 9 Isaac and Ishmael his sons buried him in the cave of Machpelah, in the field of Ephron the son of Zohar the Hittite, east of Mamre, 10 the field that Abraham purchased from the Hittites. There Abraham was buried, with Sarah his wife. 11 After the death of Abraham, God blessed Isaac his son. And Isaac settled at Beer-lahai-roi.