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(All quotations from the New King James translation unless stated otherwise).
Christians do not consider Isaac to be the firstborn son of Abraham.
Genesis 16:16 Abram was eighty-six years old when Hagar bore Ishmael to Abram.
Genesis 21:5... Abraham was one hundred years old when his son Isaac was born to him.
Muslims contend that Abraham was commanded to sacrifice his first born son (Ishmael). Scripture says no such thing.
Genesis 22:2 And he said, Take now thy son, thine only (son) Isaac, whom thou lovest, and get thee into the land of Moriah; and offer him there for a burnt offering upon one of the mountains which I will tell thee of.
Isaac was his ‘only’ son because Ishmael had been sent away when Isaac was weaned. Ishmael had gone to live in the Wilderness of Paran.
Genesis 22:8 So the child grew and was weaned. And Abraham made a great feast on the same day that Isaac was weaned. 9 And Sarah saw the son of Hagar the Egyptian, whom she had borne to Abraham, scoffing. 10 Therefore she said to Abraham, "Cast out this bondwoman and her son; for the son of this bondwoman shall not be heir with my son, namely with Isaac." 11 And the matter was very displeasing in Abraham’s sight because of his son. 12 But God said to Abraham, "Do not let it be displeasing in your sight because of the lad or because of your bondwoman. Whatever Sarah has said to you, listen to her voice; for in Isaac your seed shall be called. 13 "Yet I will also make a nation of the son of the bondwoman, because he is your seed." 14 So Abraham rose early in the morning, and took bread and a skin of water; and putting it on her shoulder, he gave it and the boy to Hagar, and sent her away.
Genesis 22:20 So God was with the lad; and he grew and dwelt in the wilderness, and became an archer. 21 He dwelt in the Wilderness of Paran; and his mother took a wife for him from the land of Egypt.
The Hebrew word for ‘only’ does not mean ‘firstborn’. It has the alternate meaning of ‘the beloved’. This is clear from the Septuagint translation.
Septuagint Genesis 22:2 And he said, Take thy son, the beloved one, whom thou hast loved––Isaac,
The Christian understanding is explained by Paul.
Romans 9:7 nor are they all children because they are the seed of Abraham; but, "In Isaac your seed shall be called." 8 That is, those who are the children of the flesh, these are not the children of God; but the children of the promise are counted as the seed. 9 For this is the word of promise: "At this time I will come and Sarah shall have a son."
Galatians 4: 21 Tell me, you who desire to be under the law, do you not hear the law? 22 For it is written that Abraham had two sons: the one by a bondwoman, the other by a freewoman. 23 But he who was of the bondwoman was born according to the flesh, and he of the freewoman through promise, 24 which things are symbolic. For these are the two covenants: the one from Mount Sinai which gives birth to bondage, which is Hagar— 25 for this Hagar is Mount Sinai in Arabia, and corresponds to Jerusalem which now is, and is in bondage with her children— 26 but the Jerusalem above is free, which is the mother of us all. 27 For it is written: "Rejoice, O barren, You who do not bear! Break forth and shout, You who are not in labor! For the desolate has many more children Than she who has a husband." 28 Now we, brethren, as Isaac was, are children of promise. 29 But, as he who was born according to the flesh then persecuted him who was born according to the Spirit, even so it is now. 30 Nevertheless what does the Scripture say? "Cast out the bondwoman and her son, for the son of the bondwoman shall not be heir with the son of the freewoman." 31 So then, brethren, we are not children of the bondwoman but of the free.
The apostles believed that the promises made to Abraham came through Isaac.
Hebrews 11:17 By faith Abraham, when he was tested, offered up Isaac, and he who had received the promises offered up his only begotten son, 18 of whom it was said, "In Isaac your seed shall be called,"
James is clear.
James 2:21 Was not Abraham our father justified by works when he offered Isaac his son on the altar?
Those baptised into Christ become heirs of the promise made to Abraham.
Galatians 3:29 And if you are Christ’s, then you are Abraham’s seed, and heirs according to the promise.
The Muslim claim that both Jews and Christians have altered scripture to replace Ishmael with Isaac is so outrageous as to beggar belief. Experience teaches that men never let reason and commonsense get in the way of what they want to believe.
Christians were astray from the Bible by the 4th century with their nonsense of a ‘triune’ God and a Christian ‘priesthood’.
Muslims are astray from the Bible because they pretend that Arabs rather than Jews are the ‘people of God’.
Christ is a Jew – a descendent of Isaac not Ishmael. Christ died (not withstanding Muslim attempts to rewrite history) to save us from our sins. He was raised from the dead the third day so that we might have confidence that he is the promised Messiah.
Jesus (who is the son of God not God the son) said:
John 4:22 "You worship what you do not know; we know what we worship, for salvation is of the Jews.
John 8:24 "Therefore I said to you that you will die in your sins; for if you do not believe that I am He, you will die in your sins."
Mark 16:16 "He who believes and is baptized will be saved; but he who does not believe will be condemned.
John 15:13 "Greater love has no one than this, than to lay down one’s life for his friends. 14 "You are My friends if you do whatever I command you.
His commandments (ignored by most of Christendom with tragic consequences) are:
Matthew 22:37 Jesus said to him, "‘You shall love the LORD your God with all your heart, with all your soul, and with all your mind.’ 38 "This is the first and great commandment. 39 "And the second is like it: ‘You shall love your neighbor as yourself.’ 40 "On these two commandments hang all the Law and the Prophets."
Our neighbour includes our enemy:
Matthew 5:44 "But I say to you, love your enemies, bless those who curse you, do good to those who hate you, and pray for those who spitefully use you and persecute you,
Here lies the difference between the doctrine of Christ and the doctrine of the Muslims.
The Bible is full of prophecies of which the return of the Jews to the land of Israel is but one. An open minded perusal of scripture will show that it has one author and that is God. Failure to read scripture and apply it in our lives will lead not to the fiction of eternal torment but to eternal death.
If you want to come to grips with what the Bible really teaches, why not take the free online Bible study course available on our website, www.thisisyourbible.com? This course will give you a background in the major themes of the Bible from Genesis to Revelation. As with everything we offer, there is no cost to you other than your time and effort... You will also have a personal tutor to whom you may pose questions either from the course itself or those questions which come to you as you read the Bible.
I hope this helps.