A thoughtful meditation on death
This is not a film about surviving, this is a film about dying. How should we face the cruel inevitability of the end coming for us all? Perhaps you are afraid to live, as Ottoway is in the beginning with a gun in his mouth. Most people are afraid to die, like the bleeding man Ottoway comforts in his final moments. The poem his father wrote is a bit on the nose, but it perfectly encapsulates what happens in The Grey.
The wolves are literally and figuratively death, coming to drag away the living and devour them. When the void is staring at you, do you fight? Run in fear? Deny it and act tough? Or find a modicum of peace and acceptance? Ottoway knows the answer, but he wants a power higher than himself to acknowledge it. For him, that higher power doesn't exist or if it does, it's unwilling to intervene. I believe it's the latter that he finds at the end, when he curses towards the sky.
God is just as cruel and incomprehensible as death; in fact, death is really the only God. Faced with the pain and unfairness of existence, what is the one thing humanity can do? We love each other, not just care for or take care of, but truly love each other. Wolves, ice, plane engines, cancer -- these things cannot love us or hate us, either. Love is a spiritual act, which is what Ottoway understands at the end of the film. And in loving, he is redeemed and accepts his death.
It's not about the will to live -- it's about the will to die, which is much more terrifying, honest, and powerful.
p.s., I think this is a deeply Gnostic Christian story, but that is beyond the scope of this.