Of these bold spontaneous doctrines none is more conspicuous than that of the intercourse between all the members of Christ, "those who have gone before us with the sign of faith" and those "who wait till their change comes, till this corruptible puts on incorruption." A Christian called upon his dead to pray for him in the realms of light, he called upon God to give to his beloved a place of light and refreshment, he besought the confessors gone to their reward to pray for both them and him. So strong was this belief in a holy and indissoluble union between the members of the one Church and the one Body of Christ, that at every celebration of the liturgy the whole body of the faithful were understood to be present--either really or mystically; and thus the Commemoration of the Living in the mass speaks of those (present) who offer and those (absent) for whom they offer the sacrifice of praise, as all equally "standing round about." And as they offered and prayed for those who were with them in the same town, so they offered and prayed for those who were already with Christ--_in bono in Christo_. The three commemorations of the Roman Canon, the _Memento Domine ... omnium circumstantium_ of the living, the _Communicantes et memoriam venerantes_ of the martyrs, and the _Memento ... qui nos praecesserunt_ of the dead, may be thought of as liturgical features crystallised in the catacombs. It is easy to see too how the funeral celebrations of the liturgy--given this initial idea of intercommunion and intercession among all Christians living and dead--extended the idea of eucharistic sacrifice. How easily the oblation of Christ--the Christian's one offering--became the means of intercessory prayer for all men and all occasions, and gave rise to the requiem mass, the mass for some special grace, the mass of thanksgiving, the mass in commemoration of a saint. Bold treatment of sacred things belongs naturally to an age when the _sentiments_ of the faith, aspiration and hope, outrun dogma--before unfaithfulness in doctrine urged upon the early Church and its leaders the necessity for stricter definition, or unfaithfulness in life had made it easier to substitute a hard and fast creed for "the weightier matters of the law." The symbolism and inscriptions of the catacombs testify how freely such elements were at work there. Take as an instance the fresco representing Christ on a throne giving a book to Peter, with the legend, _Dominus legem dat_, "the Lord gives the law." In other examples of this subject Peter is replaced by some simple but faithful disciple--"the Lord gives the law to Alexander--to Valerius." The allusion is to the "tradition of the Gospel" in baptism; it is not hierarchical.