Why do we celebrate Halloween?

Halloween seems likes a fun, exciting holiday, but what are we really celebrating? Children dress up in scary costumes to fill their faces with candy, candy and more candy. Are really celebrating satanic things or just dressing up to see how fun it is to scare people and get candy. Halloween can be all fun and games, but what are we telling people? Maybe we dream or wish of being something we are not and show it on the only holiday that you can. People dressing up in costumes might be showing there personality or just trying to be different. I'm not saying Halloween is a horrible holiday, it is just filled with mystery. In this holiday we aren't worshopping an evil things or hurting anyone, this holiday is just us kids or adults having fun and showing a different side of us and eating a lot of candy in the process.