Revelation

“For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who suppress the truth in unrighteousness, because that which is known of God is revealed in them, for God revealed it to them. For the invisible things of him since the creation of the world are clearly seen, being perceived through the things that are made, even his everlasting power and divinity; that they may be without excuse. Because, knowing God, they didn't glorify him as God, neither gave thanks, but became vain in their reasoning, and their senseless heart was darkened.” (Romans 1:18-21 NASB)

Theologians, philosophers, and apologists have made significant comments in relation to Romans 1:18-21.

Here are a few of them:
1. The revelation of God in nature is mediate, but it is so manifest and so clear that it does not necessitate a complex theoretical reasoning process that could be achieved only by a group of geniuses. If God's general revelation is in fact "general," in that it is plain enough for all to see clearly without complicated cosmological argumentation, then it may even be said to be self evident. The revelation is clear enough for an unskilled and illiterate person to perceive it. The memory of conscious knowledge of the trauma encounter with God's revelation is not maintained in its lucid, threatening state, but is repressed. It is "put down or held in captivity" in the unconsciousness. That which is repressed is not destroyed. The memory remains though it may be buried in the subconscious realm. Knowledge of God is unacceptable, and as a result humans attempt to blot it out or at least camouflage it in such a way that its threatening character can be concealed or dulled. (Sproul, R.C, Gerstner, John and Arthur Lindsey. Classical Apologetics: A Rational Defense of the Christian Faith and a Critique of Presuppositional Apologetics. Grand Rapids, MI: Zondervan Publishing.1984, 46-59).

2. Former atheist J. Budziszewski:
I am not at present concerned to explore Paul’s general claim that those who deny the Creator are wicked but only his more particular claim that they are intellectually dishonest. Notice that he does not criticize nonbelievers because they do not know about God but ought to. Rather, he criticizes them because they do know about God but pretend to themselves that they don’t. According to his account, we are not ignorant of God’s reality at all. Rather, we “suppress” it; to translate differently, we “hold it down.” With all our strength we try not to know it, even though we can’t help knowing it; with one part of our minds we do know it, while with another we say, “I know no such thing.” From the biblical point of view, then, the reason it is so difficult to argue with an atheist—as I once was—is that he is not being honest with himself. He knows there is a God, but he tells himself that he doesn’t. How can a person explain how he reached new first principles? By what route could he have arrived at them? To what deeper considerations could he have appealed? If the biblical account is true, then it would seem that no one really arrives at new first principles; a person only seems to arrive at them. The atheist does not lack true first principles; they are in his knowledge already, though suppressed. The convert from atheism did not acquire them; rather, things he knew all along were unearthed. ( Giesler, N. L. and Paul K. Hoffman. Why I Am A Christian. Leading Thinkers Explain Why They Believe. Grand Rapids, MI: Baker Book House. 2001, 49).