God Begins and Finishes All Things

O God, in your loving kindness
you both begin and finish all good things;
grant that as we glory in the beginnings of your grace,
so we may rejoice in its completion;
through Jesus Christ our Lord. Amen.

Source: Leonine Sacramentary, 440

Source of this version: Modified from http://womenofchristianity.com/page/2/

Also found here: Ancient Collects and Other Prayers, Ed. by W. Bright: J.H. & Jas. Parker, London, 1902, p. 92 #1

Also found here:  Prayers Ancient and Modern by Mary Wilder Tileston, Boston, Little Brown, 1914, p. 165 #2