Prior to becoming a Christian our minds were bound by sin and blinded by Satan.
Our minds were depraved, darkened, and distant from the things of God. 

"For when the world with all its earthly wisdom failed to perceive and recognize and know God by means of its philosophy"

However, now we have come to Christ the blinders have been removed, the bondage of sin is broken and so the light of God’s truth is able to set us free