|As the correct lineage of God’s chosen people as prophesied to the patriarch Abraham is through his son Isaac, the son that God intended to be His people, only Judaism and Christianity are truly Abrahamic religions.
Called “the father of the faithful” (compare Romans:4:11), Abraham obeyed God’s instruction to leave his native Ur and move to Haran.
Notice his example of unquestioning obedience: “Now the LORD had said to Abraham ‘Get out of your country, from your family and from your father’s house, to a land that I will show you. I will make you a great nation; I will bless you and make your name great; and you shall be a blessing …’ So Abram departed as the LORD had spoken to him …” Hebrews:11:8 adds: “And he went out, not knowing where he was going.”
God was working with Abraham to establish him and his descendants in the land of Canaan (later called the Promised Land and often referred to as the Holy Land, this is modern Israel).
At the crossroads of Asia, Africa and Europe, this area was ideal for God’s chosen people, who were to be an example to the rest of the world (Deuteronomy:4:5-8).
On arriving in the new land, God promised Abraham that He would give the land to his descendants, (Genesis:12:7) His chosen people, Jews and Christians.
“And the LORD said to Abram,… ‘Lift your eyes now and look from the place where you are—northward, southward, eastward, and westward; for all the land which you see I give to you and your descendants forever’” (Genesis:13:14-15).
God added: “And I will make your descendants as the dust of the earth; so that if a man could number the dust of the earth, then your descendants also could be numbered” (verse 16). Significantly, God later changed Abram’s name to Abraham (Genesis:17:5). His earlier name meant “high (exalted) father.” God renamed him “father of a multitude,” saying, “I will make you exceedingly fruitful; and I will make nations of you, and kings shall come from you” (verse 6).
At the time these prophecies must have seemed ironic to Abraham, for his wife Sarah was barren. Her infertility was to be very significant in the development of the modern Middle East. God promised Abraham in Genesis:15:4 that he would have an heir: “one who will come from your own body.”
Impatient, Sarah told Abraham to take her Egyptian handmaid Hagar and to produce a child by her. This took place “after Abram had dwelt ten years in the land of Canaan” (Genesis:16:1-3). Thus, Ishmael and his descendants are a product of Abraham’s disobedience.
Abraham’s first son is born
“So he went in to Hagar, and she conceived. And when she saw that she had conceived, her mistress became despised in her eyes” (Genesis:16:4). The relationship between Sarah and Hagar quickly deteriorated and Hagar fled. But a divine message was given to Hagar, telling her to return. It also reassured her that her son would have many descendants—but descendants with traits that would be evident throughout their history: “I will so increase your descendants that they will be too numerous to count … You are now with child and you will have a son. You shall name him Ishmael ['God hears'], for the LORD has heard of your misery. He will be a wild donkey of a man; his hand will be against everyone and everyone’s hand against him, and he will live in hostility toward all his brothers” (verses 10-12, New International Version).
Summary: God’s people are the descendants of the promise, of Isaac. The Abrahamic faiths are ONLY Judaism and Christianity. The opposition in all things come through the disobedience of Abraham, his son Ishmael. “his hand will be against everyone and everyone’s hand against him, and he will live in hostility toward all his brothers“. This is Islam and it is NOT of the promise and thus NOT an Abrahamic faith.