Romans 1:21-23, The Foolish Heart
The person described in verse 21 as having a “foolish heart” lacks spiritual sight. He wilfully ignores God. He is an ungodly person who turned his back on God and revealed the state of his lawless heart (v22). The greatest fool of all, therefore, is a person with the greatest intelligence who disobeys God. Paul uses the Greek word “moros” from which we receive the English “moron”. There is a stubborn streak in the person described here.