What the Christians are celebrating is the resurrection of Jesus. Here is that story.
Either at dawn or at the rising of the sun or when it was still dark, either the two Marys or the two Marys plus James's mother Salome or Mary Magdalene and Joanna and James's mother Mary and some other women or just Mary Magdalene, went to see the tomb or they brought spices to help stop the stink of the rotting corpse or I guess the body was already preserved by Nicodemus beforehand, but when they got there the tomb was already open or it wasn't, and there was an angel or a young man or two men or two angels waiting there, and the angel was sitting on the stone or the young man was in the tomb or both men were in the tomb. Also there was an earthquake, or not in the other versions.
And then one of the people there either said not to be afraid and that Jesus was risen or he admonished them not to look for the living among the dead or he or they asked the women why they were crying.
Afterwards, the women told everybody else what happened or they didn't.
Then Jesus appeared in Galilee or in Emmaus or in a room in Jerusalem, and when he appeared he appeared to eleven disciples or two disciples in the country or to ten disciples or to Peter and then to the twelve, even though Judas was already dead (to fulfill a nonexistent prophecy either by hanging himself or by exploding) so there's no way to know who the 12th disciple was. When he appeared to them, Jesus either could be touched or he couldn't. The disciples either believed the messenger(s), or they didn't.
When he appeared, some worshipped and some doubted, or not, or they were just real happy and Jesus gave them a blessing. After that, Jesus stayed on the Earth for the rest of the day or for at least eight days or for forty days. Then he ascended from Jerusalem or from Bethany or from the Mount of Olives, or he didn't.
And that is the Easter story. I think. Maybe you should ask your Christian friends to clarify it for you and to make sure that they know the story.
It's not just the inconsistencies that worry me. How many cases of a person rising from the dead have you witnessed? Does this not violate everything we know about life?