Jesus Christ is God who came in the flesh. He was born of the virgin Mary and lived a perfect, sinless life so He could pay for our sins, YOUR sins on the cross at Calvary (the hill he was crucified on). His death, agony and separation from God the Father on the cross paid for our sins so that you and I can be forgiven.
This is all true, factual history that we have recorded not only by the writers of the new testament, but prophesied by God through the writers of the old testament. We even have period historians outside of the Bible who wrote concerning the death of Jesus and most importantly even His resurrection and belief in His resurrection is recorded outside the Bible.
No, the belief that Jesus rose from the dead was not invented later, it is factual history that He has defeated death and is alive today in Heaven. His resurrection is the proof of His power to save and if you want to hear more about how you can be saved I want you to send me a PM and we can discuss Jesus Christ my Lord and Saviour.
He's coming back soon. It's time to get ready.