Deep calls to deep at the thunder of your cataracts; all your waves and your billows have gone over me.
Calvin interprets the depths referred to in Psalm 42:7 very negatively: When once [God's] anger is kindled against us, there will be not only one depth to swallow us up, but depth will call unto depth. In other words, when one deep calls to another, I am well and truly sunk.
But I would disagree with him. Yes, perhaps the first deep is the depth of despair, the misery in which I find myself. And yes, when that's where I am, it's usually due to my own doing. But I think there's another interpretation for that second depth. And it's quite scriptural.
Here are a couple of verses, one from each testament:
For the Spirit searches everything, even the depths of God.
—1 Cor. 2:10b
Can you find out the deep things of God? Can you find out the limit of the Almighty?
Thus, when I am in over my head—even (especially?) when I'm in so deep that I can't save myself—the very depths that surround me call out to the deep things of God.
Better yet, when I am in the depths of despair and cannot help myself, could it be that the first deep in Psalm 42:7 is, in fact, the depths of God calling to me in the place where I am—that being the aforementioned second deep? Theologically, this makes more sense, since God does the calling, and I respond not of my own power, but through the Spirit at work in me.
I am in over my head, Lord, and I cannot save myself. Though I am deaf to you in my current state, yet by the power of your Spirit and through the work of Christ on the cross, I have hope that I can hear and respond. Even now, I am beginning to realize that my depths have delivered me into your depths. And for that I am eternally grateful. Amen.