A self-indulgent heart…

A self-indulgent heart becomes a prison and chain for the soul when it leaves this life; whereas an assiduous heart is an open door.
–Saint Mark the Ascetic (Fifth Century)

The last day…

Do not live in fear of the last day, as though it were a thief coming to wreck your house while you sleep; but keep watch, and amend your life this day. Why put it off till tomorrow? If your life is to be long, let it be happy as well as long. No one puts off a good long dinner; and you would like a long evil life! If it is to be long, it will be all the better for being good. If it is to be short, it is as well that its fruits should last.
— Saint Augustine (354-430)

After your death…

Don’t be deceived regarding the knowledge of what will be after your death: what you sow here, you will reap there. After leaving here, no one can make progress. Here is the work, there the reward, here the struggle, there the crowns.
–Saint Barsanuphius the Great (Sixth Century)

Keep our death in mind…

If we were to keep the imminence of our death in mind, we would never be overcome by sin: lust which is fleeting would not reign over us; we would never harbor anger against another human being; we would not love the possessions which pass away; and we would forgive every person who offended us. Therefore, beloved, let’s be zealous in carrying out the work we have committed ourselves to, and let’s travel to the end of the road on which we have begun our journey.
–Saint Athanasius the Great (c. 296-373)