So, now we know what the difference is between Christianity and all other beliefs, the greater question now is, ‘Why. Why the need for and time spent on all of history?’
God existed in eternity past and everything was perfectly fine with Him. He had peace and a pleasant existence. But at some point God decided that is would be better to share all of His life and abilities with others, thus history.
Initially God had a home in eternity past.
But when He created angels, and then after that the universe, Gods home in heaven was separate from that of the angels. They had their existence and God had His.
Problems ensued as we all know. Lucifer, became lustful and arrogant, and all of the angels followed in his footsteps in sin. They all rejected God, and that led to a policy for their return, lest they be tried in a court of law, convicted and condemned to a permanent and eternal separation from God.
Two-thirds returned to God and one-third of the angels rejected God and remained behind Satan.
Satan and all of his followers, were tried and convicted of their crimes and sentenced to the Lake of Fire, which is eternal separation from God and from everything else.
Satan protested and in effect appealed that decision, and thus human history was begun in order to settle the issue once and for all.
Throughout human history, Satan has demonstrated his guilt through his promotion of lies, and suffering and evil and wickedness and so forth. God is in the process of demonstrating His truth and grace and fairness and plan, through the free will decisions of man.
But still, God and man live separate lives. God still has His residence in heaven, and man has his residence on this earth. Both are separate, and thus sin and evil continue to exist.
So then God began revealing His plan details while He walked in the Garden with man, and yet man sinned. God revealed his requirements to man during the pre-flood era (the sacrifices of Cain and Abel), and yet most of humanity rejected God.