Conor Cunningham says that the relationship between nature and grace is at the centre of everything, from metaphysical debates to football. Having just watched The Tree of Life for the severalth time, the following was a timely video to supplement Terrence Malick's cinematic exploration of this ubiquitous relationship:
The Book of Job, from which Malick plucks a verse to launch his exploration, has an interesting perspective on this relationship: In response to the questioning of His grace, God responds with nature.
Any time nature and grace appear in a theological discussion it is always helpful to ask the question, What would Karl Barth say? He might say something along the lines of "Grace is the internal basis of nature, and nature is the external basis of grace." But more than that, he would point to Jesus. To talk about "nature" and "grace" outside of the incarnation is to talk nonsense as a Christian. In Jesus's human nature, through his concrete form, grace and truth are made known. In Jesus, nature and grace are seen to be not two things but one.
But there is a particularity about that sentence that is not always respected. Materialist theology -- or atheology -- tends to collapse grace into nature. Zizek, for example, sees the church not as the people of God in the belonging sense of the word "of" but in the sense of her now being the very being of God, the "community of the holy spirit" that continues on the life of the divine even after his death on the cross. The distinction between Creator and creature that the Bible -- and more importantly, Barth! -- is eager to maintain is erased. There is nothing outside of nature. In seeking to harmonise nature and grace we have equated totality with infinity. Christian theology cannot do this if it is to remain both Christian and theological.
To bring a contemporary cultural reference in to the mix, this is why it is misguided to quote approvingly the line "To love another person is to see the face of God" from Les Miserables. God is love, but love is not God. Much better to say (or sing) something like "To see the image of God in another is to begin to love them". The difference is subtle but crucial.