Romans 1 21
because even though they knew God, they did not praise him or thank him, but instead their thinking about God turned into complete foolishness, and darkness filled their empty minds.
Compare with other 3 random translations
KJV Romans 1:21because 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.
AMP Romans 1:21For even though they knew God [as the Creator], they did not honor Him as God or give thanks [for His wondrous creation]. On the contrary, they became worthless in their thinking [godless, with pointless reasonings, and silly speculations], and their foolish heart was darkened.
EAS Romans 1:21Those people really knew about God. But they did not respect him as a great God, and they did not thank him. They did not even think clearly any more. Their minds became confused and they did not understand God's message.