A question arises regarding the angels who dwell with us, serve us and protect us, whether their joys are equal to those of the angels in heaven, or whether they are diminished by the fact that they protect and serve us. No, they are certainly not; for the work of the angels is the will of God, and the will of God is the work of the angels; their service to us does not hinder their joy nor their working. If God told an angel to go to a tree and pluck caterpillars off it, the angel would be quite ready to do so, and it would be his happiness, if it were the will of God.

Sermon IV : True Hearing - Meister Eckhart's Sermons (1909)