Easter

Many invited me to join them to church for Easter. Many asked me why i don't go to church for Easter. I was one hand holding my dinner while another was opening door to get in my apartment when , again a colleague in his senior age asked me to join him as he is going to church now. "Er..... maybe not". He was surprise that i refused. Me too puzzling why are these Christians celebrating Easter? I know Easter is the day to remember the resurrection of Christ but if i remember well, in the Bible, Christian was told and asked to remember Christ's Death not the Resurrection nor the Birthday (Christmas?). I just follow instruction (good excuse :p)