Genesis 21

Now the Lord was gracious to Sarah as He had said, and the Lord did for Sarah what He had promised. Sarah became pregnant and bore a son to Abraham in his old age, at the very time God had promised him. Abraham gave the name Isaac to the son Sarah bore him….But Sarah saw that the son whom Hagar the Egyptian had borne to Abraham was mocking, and she said to Abraham, “Get rid of that slave woman and her son, for that woman’s son will never share in the inheritance with my son Isaac.” The matter distressed Abraham greatly because it concerned his son. But God said to him, “Do not be so distressed about the boy and your slave woman. Listen to whatever Sarah tells you, because it is through Isaac that your offspring will be reckoned. I will make the son of the slave into a nation also, because he is your offspring.” ‭‭Genesis‬ ‭21:1-3, 9-13‬ ‭NIV‬‬

With the birth of Isaac, Abraham and Sarah now had the son that God had promised them. The Bible clearly states that Isaac was the son that God had promised to them, and the one through whom all nations would be blessed.  Jesus Christ was a descendant of Isaac, and this was the blessing that God was talking about.  Muslims believe that Ishmael was Abraham’s promised son, since he was the first born. This is based on the Quran (Koran), written by Muhammad in 600 A.D., which is 2100 years after Moses wrote the book of Genesis. Everyone should be cautious and discerning when discussing religions that have come after Christianity, especially with supposed prophets hearing a “new” word from God.  In these circumstances we need to remember Proverbs 30:5-6 “Every word of God is flawless; He is a shield to those who take refuge in Him. Do not add to His words, or He will rebuke you and prove you a liar.”