What changed when the Law was given to the world?
When the Law was given, the whole world became responsible and guilty before God, for now adultery, thieving, coveting, and all the Ten Commandments were clearly sin with no excuse. Previously, without written Law, people could not be charged with breaking it. Paul explains the Law was added because of transgressions until the promised seed should come.
Les explains that before the Law, people's wickedness could not be put to their account because they weren't breaking any written Law. At the Great White Throne, the books won't be opened for them the same way as for those since the Law; they will be judged, but God cannot say, 'Look at all the Law breaking you did,' because they had no Law. You can't break a Law if there isn't one. But as soon as the Law was given, the whole world became responsible. There was no question: adultery is sin, thieving is sin, coveting is sin, all the way through the Ten. All the world has now been made guilty because there is no excuse. People can no longer say, 'I didn't know there was a Law against that.' Now they know, and that's what it means. Back in Galatians, Paul writes, 'Wherefore then serveth the Law, or why was the Law given? It was added because of transgressions, until the seed should come to whom the promise was made, and it was ordained by angels in the hand of a mediator.' In other words, this whole covenant promise made.