Ephesians 4:18
“being darkened in their understanding, excluded from the life of God because of the ignorance that is in them, because of the hardness of their heart.”
Why were they darkened in their understanding? Romans 1:21 says, "For even though they knew God, they did not honor Him as God or give thanks, but they became futile in their reasonings, and their senseless hearts were darkened." They didn't honor God, nor were they thankful. They didn't fear God. Proverbs says fearing God is the beginning of wisdom. Which means to do what He says.
God gave us all the freedom to do what we want. We all love that. It includes the freedom to disobey. That's what these are doing. He wants us to use that freedom to choose Him. David describes that in Psalm 63:1b "O God, You are my God. Earnestly I seek You; my soul thirsts for You. My body yearns for You in a dry and weary land without water." He is choosing God.
Sin does have it's allure. Hebrews 11:25 says, "Choosing rather to suffer affliction with the people of God, than to enjoy the pleasures of sin for a season." It's allure is like a fish seeing a shiny lure. Once partaken we are stuck. God can free us, unfortunately we often don't want freedom. We enjoy sin so much we want to stay with it.
As we ignore God and His Word, our understanding gets darkened. The next verse from the Romans passage says, "Professing to be wise, they became fools." They don't see it. Their understanding is darkened.
I John 1:5 says, "And this is the message that we have heard from Him and we preach to you, that God is light, and in Him is no darkness at all." When we turn our backs on God, we approach darkness. We don't see things as we should. Conversely, when we go to God, our understanding is brightened. David says in Psalm 119:99, "I have more insight than all my teachers, for Your testimonies are my meditation."
When we ignore God our hearts get hardened. Not only is our understanding dimmed, but our hearts get hard. We choose darkness and we stubbornly cling to it. We become resolute about it.
God will send warnings and we will get insights to flee sin. If we accept it, He gives more insight. If we ignore again, then our hearts get harder and our understanding even darker.
Lord, help us to obey Your. Help us to see the folly of our ways and flee sin.