Those who study the nature of God sometimes consider: Is human reason capable of knowing God by its own light, from the natural world and from human nature? I suspect this is one of the times when we, seeking God, and arguing amongst ourselves over how we can know God -- or about how capable we may be -- manage on both sides to miss the point. Once we accept that question as a starting point, we have accepted a very questionable premise.
Both sides of the argument acknowledge that we can look at the natural world and the nature of man and deduce many things about God. We may hold to humility, and to God's place in our abilities, by pointing to the image of God within us as the source of this light of reason. We may argue that man's reason is capable, either by itself or with the grace of God of reasoning from the natural world to true knowledge of God. We may argue that man's reason is not capable by itself: our self-interest gives us the capacity for self-deceit.
But does God want our knowledge of him to be based solely on the natural world and human nature? Doesn't God ask for our knowledge of him to be based also on his acts of love, mercy, and compassion? (Even if we were to deduce God's love, mercy, and compassion from the natural world, what would that be worth if we did not see his actual actions among people? Do we overlook God's actions in the world because we do not recognize them, or because we do not value them? Or are we more interested in what our human reason can do blindfolded, and less interested in how much more we could know without the blindfold? Do we ever ask whether God has asked us to use that blindfold, or whether he considers it a useful thing to know, what we would reason about him if we overlooked his actions in the world? And why would we place the blindfold just there, so as to hide from our view God's actions among humanity?)
Doesn't God ask for our knowledge of him to include his actions and his continuing presence in the world, rather than simply the world's existence? Doesn't God ask for our knowledge of him to be based on his promise of faithfulness? Doesn't God desire and intend that true knowledge of himself includes not merely reasoning about him but knowing him and hearing him, not only from the heavens glorifying him in the ineffable language, but in plainer words in language that we understand? Doesn't knowing God include knowing that he is not a passive and hidden God, but the living and present one? If we try to know God from reason and nature alone, either we are not that interested in knowing him fully, or we are considering a very different kind of God than the Christian God.
There is a scene in the American sitcom The Office in which one character, sitting outside the CEO's luxurious home, goes through the CEO's trash and finds clues that the man is wealthy. He prides himself on having deduced this from the trash. But he overlooked the mansion and headed for the trash; he also overlooked that he actually knows the man himself.
So in the end, my question would be: what kind of "knowledge" of God do you get by knowing God based on reasoning from the natural world? Is this the kind of knowledge of God that God wishes us to have? Is this the highest and best kind of knowledge of God? If it is not, then we must say: "Not really, we can't know God in the ultimate way from things other than God. We know God better when we approach God."