Absurdity of Blasphemy (Leviticus 24:20-23) (LD 36)

We might think that blasphemy is not that big of a deal because it is just speaking a word that is careless.  So, if someone just says something that is careless then why does the Lord command the Israelite child to be executed when he blasphemes the Name?  Is the Lord just being petty? What does this teach us today in the church? How do we present the Lord as being a gracious God?  What is the real issue of blasphemy?