For although they knew God, they did not honor him as God or give thanks to him, but they became futile in their thinking, and their foolish hearts were darkened. (ESV)
Have you ever been ignored? How did that make you feel? I think one of the most unkind things people do to one another is to ignore each other. Imagine someone sharing with you how much they love you, and even demonstrating it by giving you various kinds of gifts, and you respond by walking away and pretending you never even heard them. That would be rude. Offensive.
Let's take this illustration a step further. Let's suppose that the person who has demonstrated love and kindness is God himself! Imagine that God has revealed himself through his created order. He has placed all of the stars and planets and galaxies exactly where they are for mankind to thrive. And imagine that man looks at that knowledge and completely ignores him. That would be rude. Offensive.
"Although they knew God, they did not honor him as God." Mankind is under the wrath of God. He has himself to blame. Even though God revealed himself to man, the response was to ignore him and to refuse to give him the glory and thanks that he was due. God is not to be ignored. When we do so we do so at our own peril.
The result of man ignoring God is that he became futile in his thinking and his heart was darkened. Have you ever talked with someone who has rejected the message of God's love so many times and you wonder how they could be so foolish? This verse tells you why. Folly is what we are left with when we choose to ignore our Creator.
God continues to reveal himself. He is revealing himself to you this very moment. Will you respond to him with gratitude? Or will you ignore him? Your response will lead to either faith or folly.