Be ever resolute, ever armed
Lorenzo Scupoli, The Spiritual Combat
Therefore be ever resolute, ever armed; trust not to the victories thou mayest have already gained, how many soever they be, seeing that man's life is a continual warfare, and the victory depends not on the success of to-day or to-morrow, but on the end.
Lorenzo Scupoli, The Spiritual Combat (19th-century English translation)
Lorenzo Scupoli (c. 1530–1610) was an Italian priest. The Spiritual Combat was first published in 1589.
More words from the saints who fought before us are in the Library.