The soul is like a ship…

The soul is like a ship: sometimes it is sunk by a mighty swell from without, sometimes from within because the bilge is overflowing. So too are we sometimes lost through sinful practices on the outside, sometimes defiled by logismoi [evil thoughts] within. So we must watch out for the attacks of the spirits from outside and drain off the impurities of the logismoi within.
–Saint Synkletike (a Desert Mother) (d. 350)

Progress by trial…

Our pilgrimage on earth cannot be exempt from trial. We progress by means of trial. No one knows himself except through trial, or receives a crown except after victory, or strives except against an enemy or temptations. The one who cries from the ends of the earth is in anguish, but is not left on his own… We have heard in the gospel how the Lord Jesus Christ was tempted by the devil in the wilderness.
–Saint Augustine (354-430)