Gregory Palamas, defending the hesychasts in the fourteenth century, distinguished God’s essence, wholly beyond participation, from his energies, which are truly God and in which the saints participate. The distinction allows Orthodoxy to affirm real union with God without confusion of creature and creator.
Divine energies
In Orthodox theology, God’s uncreated activities, in which creatures can share while God’s essence remains unknowable.
Also: essence–energies distinction