Maybe you don't vent--you just stew. A leaking, low-level irritability is a great temptation on a journey of love. You feel you have the right to be moody--you've earned it. It is a way of exacting emotional payment from a disappointing life. Grumpiness provides momentary relief, but it always involves a splitting of the self. I commit outwardly, with my hands, but not with my heart. I go through the motions of love, but anger smolders just below the surface like a simmering rant. . . . The result? I'm split. My will has slipped off the tracks of quiet surrender to the Master, and I'm just going through the motions. Life ceases to be fun. If left unchecked, my inner moodiness begins to distort my heart, and I can slip into cynicism, which begins a downward trajectory into bitterness.
Self-pity, compassion turned inward, drives this inward spiral. Instead of reflecting on the wounds of Christ, I nurse my own wounds. . . . But self-pity is just another form of self-righteousness, and like all self-righteousness it isolates and elevates. . .
The cure for a cranky soul begins by repenting, by realizing that my moodiness is a demand that my life have a certain shape. Surrendering to the life that my Father has given me always puts me under the shelter of his wings. That leaves me whole again, and surprisingly cheerful.
--Paul E. Miller, A Loving Life: In a World of Broken Relationships (Crossway, 2014), 109-10