At times God seems to give us stones impossible to digest. In these moments think of the pearl oyster: it retains the accidental grain of sand within itself for a long time, constantly bathing in it with its secretions. In due time a magnificent pearl is created. In like manner the animosities and antipathies that make their way into our hearts are seemingly indigestible pebbles. However, if we keep them wrapped in prayer, they will become pearls of love. Prayer provokes this miracle of love. Indeed, what appears to be indigestible can become real nourishment for prayer.
~ from AWAKENING TO PRAYER by A. I. Okumura