Why Jesus Really Came To The Earth

okk,sorry my understanding about Christianity must be slightly week. Would you kindly give slightly more informaition on this?

What exactly is Holy Spirit?

Mary wasnt married to God but she did concieve his child? This seems slightly odd.

Why would Joseph actually marry as women who has already concieved a baby from God? Perhaps no one know the answer about this but I would love to hear your comments.

What exactly is God in your opinion? Is he also a human like Jesus (peace be upon him)?

According my very limited knowledge I thought women egg can only be concieved by a physical form of a sperm. And if God is not physical (no one knows) or if Holy Spirit is not physical then where did the spern came from?

Now I would humbly clarify that these question in no mean asked to characterised the Mary mother of Jesus (Peace be upon him). She is as holy to us as she is to Christians.