"Let It Grow" is a spiritual ballad, often described as both a love song and a devotional religious song. It's a reflective and emotional piece, with a haunting quality. The music builds from a hushed whisper, incorporating acoustic guitar and dobro, and gradually swells into a stirring, electrified finale with bluesy licks. The opening line even references an earlier song, "Crossroads," that Clapton covered. At its heart, this song plays like a journey of quiet contemplation leading to a powerful, unfolding realization.