There is a very common accusation against those who hold to free grace. If we are saved solely by grace through faith in Christ, why can't we as Christians live however we want? You'll often hear it said that this sort of salvation isn't genuine or that it's "fire" insurance. So, the real question is this; Is there such a thing as absolute freedom to do whatever you want to do, or is there something that governs our liberty?  Charlie addresses this very common accusation in Galatians 5:13-15. 

For further reading, see Gracenotes #35 Does Free Grace Teach License and Gracenotes #84 The Christian and the Law