All God wants of man is a peaceful heart.

The saying expresses a central Eckhartian theme: God is not primarily served by external works, displays of piety, or anxious striving, but by an interior disposition of detachment and serenity. A “peaceful heart” suggests a will no longer divided by fear, self-assertion, or restless desire—an inner stillness in which the soul is receptive to God’s presence. Read this way, the line points toward Eckhart’s emphasis on Gelassenheit (letting-go) and the birth of the divine in the soul: peace is not mere calmness but a spiritual freedom that allows love and right action to flow without ego-driven agitation.