The idea of participation in heavenly worship is a fascinating perspective on the Christian Eucharistic liturgy. Although somewhat forgotten in modern times, the early church knew it as a central aspect of meaning in interpretations of the Eucharistic rite. Through this rite worshippers could see themselves in communion with angels and saints in the eternal liturgy of heaven. Interpretations along such lines emerge clearly in catechesis and homilies from the fourth century onwards, and continue to develop in the following centuries, especially in the eastern liturgical traditions. The question remains, however, what are the origins of this concept? In Participation in Heavenly Worship, Sverre Lied explores how the relations between the earthly and heavenly realms were understood within the context of Christian worship during the first three centuries CE. He argues that the idea of participation is an aspect of Christian worship that may be traced back to Jewish Christian apocalyptic mysticism, and shows how this concept, with considerable variations, was preserved and developed during the following centuries. These observations also shed new light on the appearance of the Sanctus in the Eucharistic liturgy.