Another wonderful collect, apparently (according to Blunt) an original composition by John Cosin, Bishop of Durham at the Restoration.
O GOD, whose blessed Son was manifested that He might destroy the works of the devil, and make us the sons of God, and heirs of eternal life; Grant us, we beseech thee, that, having this hope, we may purify ourselves, even as He is pure; that, when He shall appear again with power and great glory, we may be made like unto Him in His eternal and glorious kingdom; where with Thee, O Father, and thee, O Holy Ghost, He liveth and reigneth ever, one God, world without end. Amen.
Cosin's collect is obviously deliberately tied in with the Epistle reading for the day, that wonderful passage from I John 3:
BEHOLD, what manner of love the Father hath bestowed upon us, that we should be called the sons of God: therefore the world knoweth us not, because it knew Him not. Beloved, now are we the sons of God, and it doth not yet appear what we shall be: but we know that, when He shall appear, we shall be like Him; for we shall see Him as he is. And every man that hath this hope in Him purifieth himself, even as He is pure. Whosoever committeth sin transgresseth also the law: for sin is the transgression of the law. And ye know that He was manifested to take away our sins; and in Him is no sin. Whosoever abideth in Him sinneth not: whosoever sinneth hath not seen Him, neither known Him. Little children, let no man deceive you: he that doeth righteousness is righteous, even as He is righteous. He that committeth sin is of the devil; for the devil sinneth from the beginning. For this purpose the Son of God was manifested, that He might destroy the works of the devil.