As our soul grows in the love of God and journeys forth toward him, our heart's capacities also grow and expand: "Thou shalt enlarge my heart" (Ps. 119:32 KJV). But the sword cuts both ways. While our heart grows in its capacity for pleasure, it grows in its capacity to know pain. The two go hand in hand. What, then, shall we do with disappointment? We can be our own enemy, depending on how we handle the heartache that comes with desire. To want is to suffer; the word passion means to suffer. This is why many Christians are reluctant to listen to their hearts: They know that their dullness is keeping them from feeling the pain of life. Many of us have chosen simply not to want so much; it's safer that way. It's also godless. That's stoicism, not Christianity. Sanctification is an awakening, the rousing of our souls from the dead sleep of sin into the fullness of their capacity for life.
Desire often feels like an enemy, because it wakes longings that cannot be fulfilled in the moment. In the words of T. S. Eliot,
April is the cruelest month, breeding
Lilacs out of the dead land, mixing
Memory and desire. (The Waste Land )
Spring awakens a desire for the summer that is not yet. Awakened souls are often disappointed, but our disappointment can lead us onward, actually increasing our desire and lifting it toward its true passion.