When was the first bible created?
The bible is made up of 66 books written by about 40 different authors spanning from 3000BC to 80AD.
The first books of the bible are the writings of Moses also called the Torah. These books have been preserved in Israel since they have been written by the Jewish people. Until 70AD the scrolls of prophets were located in the temple in Jeresulem and copies of the scrolls were in synagogues throughout the Roman empire.
The new testament was originally written between 40AD and 90AD. These documents were considered the word of God throughout the history of the Early Church. In 325AD the First Council of Nicaea officially deemed (recognized) the common writings of the New Testament as canon (Holy Scripture). The writings had already existed, and new ones were trying to be introduced along with new, corrupt theology, so the Council gathered together to officially agree on the historical writings along with the diety of Jesus.
> ...how can one manage to write everything about another person, even his darkest secrets in the bible when the author is not that person?
As stated above, the bible is written by multiple authors. The New Testament is written by various people. Matthew and John were the actual disciples who wrote the accounts. The Apostle Paul wrote a number of letters from his first hand experences, and his writings are confirmed in the writings of Peter as being scripture. 2 Peter 3:15-16. Peter was one of the main disciples. Jude was brother of James the Disciple... etc.
2) Who wrote genesis? Moses wrote Genesis. If you read Exodus and Deuteronomy, you'll see that Moses spoke with God face to face. He went into a tent of meeting, and a cloud descended upon it and he wrote the words of God. Also geneological records were important to the people of that day. They kept geneologies all the way from adam to noah, to abraham, to moses and so on.
3) Contradictions - Most things that seem to be contradictions are things that are not examined closely. Often times something may seem like a contradiction when it makes perfect sense with the proper theological understanding. For instance, I looked up on of the contradictions that athiests claim about the bible...
John 5:31 If I bear witness to myself, my testimony is not true;
John 8:14 Jesus answered, "Even if I do bear witness to myself, my testimony is true...
They claim this is a contradiction, but if you take the time to read the context, and read the rest of the scripture taking into account that Jesus is God Himself, there is no contradiction.
Today someone asked about Genesis 1 and Genesis 2 and which day the animals were made. The Genesis 1 account was God creating Animals (from nothing). The Genesis 2 account was God looking for a Helper for Adam and He "formed" animals and sent them to Adam. Had the animals already been created? Yes. The genesis 2 account is a specific setting. Genesis 1 is a different setting, speaking of the whole earth, not the immidate area where adam was at.
It's much better to believe it all, or not believe any of it at all, than to pick and choose what to believe. I trust my very life to the bible, its accuracy, and it being the Word of God.