Grace doesn't grease the wheels of the law. Grace isn't God's way of jury rigging a broken law. It's the other way around. The law is just one small cog in a world animated entirely--from top to bottom, from beginning to end--by grace.
Sin acts as if God's original plan was for us to bootstrap ourselves into holiness by way of the law and then, when this didn't quite pan out, God offered his grace--but only the bare minimum--to make good the difference. This is exactly backwards. God's boundless grace comes first and sin is what follows.