The Birth of Jesus Christ (a.s.)
Allah tells us in the Holy Quran the story of how Sayyeda Maryam (a.s.) gave birth to Prophet Jesus Christ (a.s.). He chose her above all women of the worlds, and made her and her son a sign for all people.
Allah willed for Maryam—the believing, devout, and righteous woman—to be the mother of His Prophet Jesus (a.s.), and to give birth to him without a father. This was to make his birth a divine miracle, and to give Jesus (a.s.) the great role that Allah had chosen for him.
She was alone in the sanctuary when the angel told her that she would have a son. She was astonished, because no man had touched her and she was not unchaste. She said:
"How can I have a son while no man has touched me and I have not been unchaste?" Surah Maryam, (19:20)
The angel reassured her and told her that this was Allah's will, and that He is able to do all things:
"He said, 'Thus [it will be]; your Lord says, "It is easy for Me, and We will make him a sign to the people and a mercy from Us. And it is a matter [already] decreed."'" Surah Maryam, (19:21)
When her pregnancy began to show, she left and went to a distant place away from people. The pains of childbirth came to her near the trunk of a palm tree. There, she gave birth to Prophet Jesus (a.s.) by Allah's will. Allah says:
"So she conceived him, and she withdrew with him to a remote place. And the pains of childbirth drove her to the trunk of a palm tree. She said, 'Oh, I wish I had died before this and was in oblivion, forgotten.' But he called her from below her, 'Do not grieve; your Lord has provided beneath you a stream. And shake toward you the trunk of the palm tree; it will drop upon you ripe, fresh dates. So eat and drink and be contented. And if you see from among humanity anyone, say, "Indeed, I have vowed to the Most Merciful abstention, so I will not speak today to [any] person."'" Surah Maryam, (19:22–26)
In Surah Al-Imran, Allah mentions the angels giving glad tidings to Maryam (a.s.) of her son Jesus (a.s.):
"When the angels said, 'O Maryam, indeed Allah gives you good tidings of a word from Him, whose name will be the Messiah, Jesus, the son of Maryam—distinguished in this world and the Hereafter and among those brought near [to Allah]. And he will speak to the people in the cradle and in maturity and will be of the righteous.' She said, 'My Lord, how will I have a child when no man has touched me?' He said, 'Thus Allah creates what He wills. When He decrees a matter, He only says to it, "Be," and it is.'"
Surah Al-Imran, (03:45–47)
When Sayyeda Maryam returned to her people carrying the child Jesus (a.s.), they were shocked and amazed. They knew Maryam as a devout and righteous woman, far from any sin, so they condemned her. But she pointed to Jesus (a.s.)—as Allah had commanded her—so that they would speak with him instead of her. They wondered how they could speak to a baby in the cradle. Then Jesus (a.s.) himself answered them. This was a divine proof of Maryam's innocence, and a sign of the miracle that Allah had willed. Allah says:
"Then she brought him to her people, carrying him. They said, 'O Maryam, you have certainly done a thing unprecedented. O sister of Harun, your father was not a man of evil, nor was your mother unchaste.' So she pointed to him. They said, 'How can we speak to one who is in the cradle a child?' He said, 'Indeed, I am the servant of Allah. He has given me the Scripture and made me a prophet. And He has made me blessed wherever I am and has enjoined upon me prayer and zakah as long as I remain alive. And [made me] dutiful to my mother, and He has not made me a wretched tyrant.'"
Surah Maryam, (19:27–32)
Allah has dedicated an entire Surah to Sayyeda Maryam (a.s.) named after her. He also mentions her story in Surah Al-Imran and in other Surahs.
As for the date of the birth of Sayyeda Maryam's son, Jesus Christ (a.s.), there are different views. According to Western churches, he was born on December 25th. According to Eastern churches, he was born in early January. There are also other opinions.