While it is true that other religions have similar stories, the Bible origin have something others don’t, the answer immediately in the Garden after the fall. For after the fall man was separated from God. So the First mention of Jesus Christ is given: And I will put enmity between thee and the woman, and between thy seed and her Seed; It shall bruise thy head, and thou shalt bruise His heel. Genesis 3:15. We see here God cursing the serpent, is it any wonder most women fear and hate snakes. But He replies that the woman‘s Seed (Jesus Christ) would be virgin born and and “bruise His heel,” refer to our Lord death. Paul refers to this in Romans 16:20.
Because we in our wickedness are so evil we overall do not understand the devil and his angels started to defile mankind. While yes it is true the angels of God don’t marry and have sex, Matthew 24:30 it is not true of fallen angels. These evil being keep not their 1st estate and left their habitation, Jude 6. So that God judge them, II Peter 2:4. These are what cause the flood of Genesis, for we read this in Genesis 6:4-5. So to give mankind a chance at Redemption thru a pure man the flood was sent. So why did Israel follow the practice of utterly destroying nation at God’s command, because somehow we encounter giants again (probably one are more of Noah’s daughter-in-laws carried the gene) or perhaps other fallen angels after the flood mated with women. Many think that Paul is referring to this in I Corinthians 11:10. But God to keep His promise of a coming Redeemer for mankind keep a pure human race, no angelic blood, definitely Oriental and Black blood and possibly some White blood but nothing else.
But all this is interesting but of no real value. For the Law was a schoolmaster to bring us unto faith in Jesus Christ, Galatians 3:24. So the Promise of Christ being fulfilled by our faith, Galatians 3:15-22, teaches us these words of Christ: Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of Me. John 5:39
The Promise was also stated Isaiah 48:16-17. So why study the Bible, it is God’s love letter to His people, Luke 1:1-4. Theophilus means lover of God, Luke 1:3