Thagrastay

Legolas,
I realize it is very late in the discussion to be weighing in, but I truly feel I must. You have very real questions and very real concerns about these things and I have to remind you that the answers you are receiving are, for the most part coming from very die-hard skeptics. They are seemingly not so much trying to answer your questions to bolster the faith you seek to as much as destroy any seeds of faith you might have.
To answer your original questions I am going to add my own two cents from my own years of study and give you the best information from a spiritual point of view that I am able.
We'll let the skeptics do as they wish afterwards.
Sin is Man's will running contrary to God's.
God's will is perfect. Man's will is imperfect. We have, over all of our many generations since the first, learned to follow our own will rather than God's and to seek out our own ways rather than God's. This has resulted in iall the problems the world faces today- crime, war, hunger, death, greed, etc.
At one point in time, God established a covenant with a man named Abram, that he would make a great nation of his decendents and through his decendents, one would be born through which God Himself would deliver all of mankind.
When God gave Abram a son, God changed Abrams name to Abraham and at one point, commanded Abraham to sacrifice his son. Abraham, loving God, did not question, but did as God commanded, and led his son, Isaac up to the mopuntain top, and prepared his son for sacrifice. At the very last second, God stopped Abraham and substituted a ram instead. The point being that Abraham's fainth in God was enough, and the only son that would ever be required would be God's own, who would lay down His own life willingly.
Moses was a prototype of the Promised one that was to come, and many of the things that occurred in Moses' life time would also occur in Jesus'. The killing of the male children 2 years old and under, the escape into egypt(ian life ) for a time, the coming out of Egypt and miracles and leading of God's people and miracles and establishing of laws and deliverance.
When it came time for Moses to lead his people, the Hebrews out of Egypt, it was given to him by God to perform many great signs and wonders and cause plagues to come upon the Pharoah in order to make him release the Hebrews. The final plague was of the Pharoahs own doing- the death of every first born in Egypt.
That night, The Angel of Death visited Egypt and made Pharoah's own curse come to pass. But before hand, knowing whjat was to take place, Moses went to the Hebrew people and told them to take an unblemished (unspotted-clean) lamb and slaughter it, and take its blood and paint it on the door posts of their homes and then go and prepare to leave. And whenthe Angel of Death passed through Egypt, whenever He saw a home upon whose posts rested the blood of the lamb, Death would pass over it. So, those that believed Moses and did as he told them, their foirst born were spared and they were protected from death by the blood of the lamb. But those who did not believe, and those who did not have the blood covering their homes were not protected, and Death did not pass over. I this way, God delivered His people from the Pharoah and slavery in Egypt.
King David was also a prototype of the Promised One (Jesus) in that He was humble and Subserviant to the Will of God. That he rejoiced in the delight of God and was a man after God's own heart.
When Jesus was born, it was the fulfillment of multitides of prophecies spanning hundreds of years and many different writers. Over the course of His life, He fulfilled many more prophecies that proved He was Meschiach- the Holy One- the Messiah.
Jesus was sinless His entire life. He did not sin, even once. He was washed clean, as was the Pasover Lamb, in the river Jordan by John the Baptist, and prepared for sacrifice over the course of His ministry in many ways, right up until the Passover, when the High Priest of Israel sacrificed Him on behalf of all the Israelites and all the sins of all mankind were laid upon the man Jesus who was our symbolic Lamb, and the cross was our door post and His blood was shed and covered all the sins of all persons for all time.
And when He called out to His Father- "Forgive them, Father, for they know not what they do", He was asking that for you and me and everyone ever and interceding for us.

Jeus prayed the night before because He was a man. He knew exactly what was going to happen to Him in the next several hours. He was going to be beaten and beaten andbeaten and tortured and abandoned by his friends and accused and whipped and lashed and scourged and crucified. He knew what was coming and He asked His Father to give Him the strength to geth Him through it. In the end, He did.

Jesus died to restore all things. One perfect man, Adam, allowed sin into the world. One perfect man, Jesus, paid the price for all of it.
That is a huge concept, spiritually, but with prayer and meditation on it, it is very understandable.
Please bear in mind once more that many of the people that have commented so far do not believe in Jesus or Christianity and have said as much, and so, you must wonder about their agenda. If you would like to contact me privately, please feel free to. I would be happy to answer any questions you have or direct you to people more knowledgeable than myself who can.

__________________
"That's it! They've got the cuffs on him, he's IN the car!"