D.A. Carson, on God and prayer in the midst of suffering:
The degree of our peace of mind is tied to our prayer life (Phil. 4:6-7). This is not because prayer is psychologically soothing, but because we address a prayer-answering God, a personal God, a responding God, a sovereign God whom we can trust with the outcomes of life’s confusions. And we learn, with time, that if God in this or that instance does not choose to take away the suffering, or utterly remove the evil, he does send grace and power. The result is praise; and that, of course, is itself enjoyable, in exactly the same way that lovers enjoy giving each other compliments.
I cannot tell you how many times I have visited some senior saint who is going through serious suffering, perhaps terminal illness, only to come away feeling that it was I who benefited from exposure to a believer who was already living in the felt presence of God.
D.A. Carson, How Long, Oh Lord? p. 217-218.