God is immutable and therefore could not have been different yesterday from what He is today or shall be tomorrow.
So what made God apparently more civilized today than in the past? The answer is simple. Because in past societies violence was the norm and therefore some form of evilly punishments were required in order to avoid greater evils
For instance, had the man gathering sticks on Sabbath been left unpunished with death by stoning then God would had been eventually forced to rain down balls of fire or all over the planet.
