Sin fell into the world in the Garden of Eden, when Adam and Eve ate of the forbidden fruit from the tree of the knowledge of good and evil (Gen 2:16–17, 3:3), see The Fall of Man in The Biblical Creation and the Fall of Man. Eve then ate from the tree and gave to Adam who also ate. The woman was deceived, but the man's sin was willful disobedience. God held the man responsible for what happened.
This original sin is inherited from Adam from generation to generation through a father to his children (Rom 5:12–14, Gen 3:17–19).
Jesus Christ who is the Son of God took on flesh when he was born as a man so that he could die physically. God can’t die spiritually. Jesus shed his blood on the cross for our sin. He took the punishment (1 Pet 3:18, Heb 2:9, Mat 27:46, Mark 15:34), see
Psalm 22: the Crucifixion Psalm. Jesus is the only one who could do that (Acts 4:12), because he had no sin (John 8:46, Heb 4:15, 1 Pet 2:22, 2 Cor 5:21). If there had been sin in Jesus' life, he could only have died for his own sin but not qualified to die for mankind. That is why the virgin birth is so important to prevent original sin from Adam from being passed on to him. This qualifies Jesus to be our substitute.
Man wasn't involved in the conception of Mary, the mother of Jesus. She was conceived by the Holy Spirit in a supernatural way (Luk 1:26–27, 31, 34–35).
Jesus was born of a virgin (Mat 1:18–25). This has been prophesied by Isaiah:
- "Behold, the virgin shall conceive and bear a son, and they shall call his name Immanuel" (which means, God with us). (Mat 1:23).
- "Therefore the Lord himself will give you a sign. Behold, the virgin
(or young woman) shall conceive and bear a son, and shall call his name Immanuel." (Isaiah 7:14).
Many English translations use the word virgin (NKJV, ESV) in Isaiah 7:14,
as used in Septuagint. Some have a note that it could also be a young woman
(NASB, NIV), based on the Masoretic Text. See these versions of the Old Testament explained in Which Version of the Old Testament did Jesus Use?
Also see why Septuagint is many times more accurate and reliable than the Masoretic Text at time 43:51–46:04 in Why You Should Use the Septuagint.
The Old Testament was translated into Greek in Septuagint based on proto-Hebrew texts around 250 BC. The Greek word that is used is "parthénos", which means "virgin". It's interesting that they used the word for "virgin" so long before Jesus was born. The same Greek word "parthénos" is also used in Mat 1:23 above.
It was a blessing to have the Old Testament in Greek in the first century when the gospel was presented to the Gentiles, because Greek was a common language at that time in that area and is comparable to where English is today.
The Hebrew word that is used in the Masoretic Text is "almá", which means
"young woman". There is no case where it can be proven that "almá" denotes a young woman who isn't a virgin. The fact of virginity is evident in Gen 24:43 where "almá" is used of one who was sought as a bride for Isaac.
For more detailed information; see time 0–2:26, 7:30–9:57, and 20:34–22:24 in
Why You Should Use the Septuagint, and time 11:25–12:35 in The Septuagint (LXX).
See also time 47:36–50:55 in Matthew 1 – Genealogy, Origins, History.
We should refer to Jesus as "God with us" (Immanuel) (Mat 1:18–23). Immanuel is a declaration, a statement about the deity of Jesus Christ, see Jesus is God. Every time we say Jesus Christ, the Son of God, born of a virgin, God came as a man, we declare him Immanuel, that is "God with us".
See also Some stories in the gospels at the end of The Four Gospels.
