Mary a virgin? Isn't it more likely Joseph knocked her up, they had to cover it up and the whole lie just snowballed out of control?
Yes. Of course that's more likely. That's why a virgin birth is astounding if true.
Isaiah 7 says, "Therefore the Lord Himself will give you a sign: Behold, a virgin will be with child and bear a son, and she will call His name Immanuel."
This is fairly straight forward. Matthew and Luke include the virgin birth account to remind us all that it was predicted.
It wasn't directly taught by Jesus.
Let's think about it for a second. If I claim anything about the day I was born, where does that information come from? I do not remember the day I was born. I don't remember anything about that day. So if I were to claim some supernatural event, I can't verify it with my own memory.
So usually these kinds of claims come from ones other than the individual they are claimed about.
In this case, we know that Jesus' mother Mary was an active part of Jesus' ministry. This information could only come from the one of whom it's about. The virgin brith story rests on Mary's ability to remember and tell the truth. Luke explains in his gospel (one of the gospels where we find the account) that he gathered eye witness accounts. No doubt he spent time with Mary.
Interestingly, we don't have any place where Jesus claimed this of himself. It appears that he didn't teach anyone that he was virgin born. John's gospel doesn't say that he was, but says "the word became flesh." Mark's gospel leaves it out. That doesn't mean that it isn't true. It just means that it probably wasn't part of Jesus' teaching. It wasn't required that someone know that Jesus was virgin born form them to understand the message, and believe.
It was expected by the people of the day.
You will notice, when you study history that many religious figures claim a miraculous birth. Wether this is claimed after they lived or during their life, it is unknown on most accounts.
Alexander, the Ptolemies, and the Caesars were said to be "virgin born."
Alexander also claimed a serpent god, Phoebus, and Jupiter as his progenitors.
In these cases, why would these men claim to be born under miraculous circumstances?
Miraculous births in the ancient world were claimed to signify divinity. The son of a god would be more fitting as a king than just any ole' man. Miraculous birth was a sign, in the ancient world, that the god's had bestowed some of their power on the baby.
This brings up another question.
If the true God wanted to illustrate that his divinity had come to earth in human form, is it at least possible that God would use a method that the world already expected.
The ancient world expected rulers, and men of great power to be miraculously born. It was part of the mindset of that day. For an almighty God, it wouldn't pose any difficulty to do it.
Although I don't personally believe that Alexander was born of a serpent god, or Caesar was born to a virgin and raise by wolves. The people of the time did. (I'm assuming)
So if the people expected Kings to arrive by miraculous birth, it's not surprising to me that God might fulfill that expectation to herald the birth of the future King of the world.
Believing the virgin birth is not required for salvation.
That Jesus is virgin born is a fascinating and beautiful part of the narrative of Christ. I personally believe that it took place, but it's not presented as vital to the story. Since, as we mentioned before, it's not mentioned in two out of the four gospels.
John's gospel is the only one that is specifically written to tell people how to have eternal life. John relays Jesus' words when he says, "He who believes in the son has eternal life."
John 4 tells us what we need to believe. He says to the woman at the well, ""If you knew the gift of God, and who it is who says to you, 'Give Me a drink,' you would have asked Him, and He would have given you living water."
This shows us that we need to know two things for salvation. We need to know who it is that offers the gift, and that the gift is free eternal life given for faith alone in christ.
Basically said, we need to believe the giver and the gift.
Notice that the virgin birth is not part of that. Especially considering that John's gospel is written so that we can know how to have eternal life, and John leaves the virgin birth out completely.