There are two apparently irreconcilable aspects to the New Testament's affirmation of Natural Revelation.
On the one hand, it is affirmed that man is able to discover God's existence from examining His works in nature, because "since the creation of the world His invisible attributes are clearly seen, being understood by the things that are made, even His eternal power and Godhead" (Romans 1:20). There is not a word in this text about faith. Indeed, how can one believe in what is "clearly seen"?
On the other hand, it is equally attested that "he who comes to God must believe that He is" (Hebrews 11:6). Faith, not reason, is affirmed here. However, if faith in God's existence is necessary, how am I to have faith in what I already know? How is it possible to know and believe in the same thing?
I did not make up this problem. The mutual exclusivity of faith and reason, when both are directed to the same object and under the same aspect, has always been recognized among rational men.
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http://www.allsaintsorthodox.org/Ponderings/Pondering_2006_06_25.html