BEFORE explaining the prayers and ceremonies of holy Mass it may not be amiss to say a few words about reverence; for whenever any public celebration is to go on, it is surely our duty to understand the part, if any, which we are to take in it. The holy Mass is a public celebration even if no one but the priest and ourselves are to be seen in the place where it is offered, because the angels are always present. And it is wise to remember that, although they are not visible to mortal eyes, they can see us very well. Now, when we are present at holy Mass, our part is exactly the same as theirs to pray and be reverent. But what is reverence ? Reverence is the honor and respect which we feel for our superiors - for those who are older, wiser, or better than ourselves - shown in our outward behavior. I need not tell you that God the Father Almighty, Creator of heaven and earth, is the first and greatest of all our superiors. His name is never to be mentioned lightly, or without necessity - and tke sacrifice of the Mass is offered to Him. The Second Person of the Blessed Trinity is truly God, and in His human nature He is Jesus Christ our Lord and Saviour at "whose name every knee shall bow of them that are in heaven, of them that are in the earth, and of them that are under the earth." So you see the wicked spirits themselves are bound to show reverence to the very name of Our Lord - not from any good will, you may be sure, but because such is the command of God, which they are compelled to obey, for they are still "spirits of His that do His will." This Second Person of the Blessed Trinity, Our Lord Jesus Christ, the Redeemer of the world, is the victim offered to the eternal Father in the holy sacrifice. St. John in his wonderful vision of heaven saw the throne of God, and "four and wenty ancients fell down before Him that sitteth on the throne and adored Him that liveth for ever and ever, and cast their crowns before the throne, saying: Thou art worthy, O Lord Our God, to receive glory, and honor, and power; because Thou hast created all things; and for Thy will they were and have been created." St. John saw also in heaven: "A Lamb standing as it were slain" and "heard the voice of many angels round about the Throne;" and "The number of them was thousands of thousands, saying with a loud voice: The Lamb that was slain is worthy to receive power, and divinity, and wisdom, and strength, and honor, and glory, and benediction." There is very much more - all of it wonderfully beautiful- and you will, I hope, read it and love it some day. But surely I have written enough to make you understand how the saints and angels show reverence in heaven.