If you aren't in a state of grace, you need to go to the Sacrament of Confession before receiving the King of kings and the Lord of lords. 

I try to resist mortal sin but I do not receive Communion if I need to go to Confession.  Why would I want to eat and drink judgement upon myself?  Why would anyone wish me to do that?  I don't get the blasé attitude when it comes to preparing oneself to receive.