An excerpt from "Bible Apologetics.org" entitled, "Suppression of the Truth" states: "
When it comes to believing in God we can choose to acknowledge He exists, deny He exists, or just suppress the reality that He exists. Since the above verses from Romans [1:18-21] clearly tell us that those who deny the existence of God have no grounds to stand on because the universe screams for the existence of a Creator, those who live in sin and wickedness choose to suppress the reality of God. They believe that by suppressing this truth they will be OK. Sadly, these souls will have no excuse when they die and face a holy God at judgment because they have all the evidence they need to know that God exists.
Suppression of the truth is so dangerous because it gives one the illusion that they can go on sinning with no consequences. No wonder (Psalm 14:1) says: “The fool hath said in his heart, There is no God…” This article may be viewed at: Suppression of the Truth/bibleapologetics.org
Reference: Romans 1:18