What happened when mankind knew God but did not glorify or thank Him?
When mankind knew God but refused to glorify Him or give thanks, they became vain in their imaginations, and their foolish hearts were darkened by a judicial act of God. Professing themselves wise, they became fools. This downward progression is the track record of the human race.
Les explains that when mankind knew God, they always had a witness, but they did not glorify Him as God, neither were they thankful. Instead, they became vain in their imaginations, and their foolish heart was darkened by a judicial act of God. Professing themselves to be wise and educated, they became fools in God's sight. Les teaches that this is not only the track record of the human race in general, but also of empire after empire, nations in particular, and finally the individual—a downward track.
Because that, when they knew God, they glorified him not as God, neither were thankful; but became vain in their imaginations, and their foolish heart was darkened.