The Sabbath Commandment: Church on Saturday or God will kill you?

What should we do with that old (VERY OLD) commandment to rest/worship? on the Sabbath? Did the church somehow get confused over the centuries and make an error in switching worship from Saturday to Sunday? Or worse - will God still kill us for this (like he did to "stick collecting guy")? 
I did some research. A LOT of research. Enjoy.