Reformation Theology has a stack of quotes, some of which I have seen elsewhere. Here is a great one from Duncan: ” ‘The most insignificant sin that has ever been committed would ruin the entire cosmos, for it would mar the perfection that God created to reflect His glory. We steal God’s glory by every sin. We do not grasp the weight of our sin. Until we can bring home the ugliness of sin, Satan has another weapon in his locker.’ “