Pope Saint Gregory the Great

If we knew at what time we were to depart from this world, we would be able to select a season for pleasure and another for repentance. But God, who has promised pardon to every repentant sinner, has not promised us tomorrow. Therefore we must always dread the final day, which we can never foresee. This very day is a day of truce, a day for conversion. And yet we refuse to cry over the evil we have done! Not only do we not weep for the sins we have committed, we even add to them. 

-- Pope Saint Gregory the Great 

Saint Josemaria Escriva

The rosary is said not with the lips alone, muttering Hail Marys one after the other. … For a Christian vocal prayer must spring from the heart, so that while the rosary is said, the mind can enter into contemplation of each one of the mysteries.

-- Saint Josemaria Escriva

Saint Catherine of Siena

Eternal Trinity, Godhead, mystery deep as the sea, you could give me no greater gift than the gift of yourself. For you are a fire ever burning and never consumed, which itself consumes all the selfish love that fills my being. Yes, you are a fire that takes away the coldness, illuminates the mind with its light, and causes me to know your truth. And I know that you are beauty and wisdom itself. The food of angels, you gave yourself to man in the fire of your love. 

-- Saint Catherine of Siena

Saint Peter Damian

Let us detach ourselves in spirit from all that we see and cling to that which we believe. This is the cross which we must imprint on all our daily actions and behavior.

-- Saint Peter Damian

Saint Mark the Ascetic

When Scripture says, 'He will reward every man according to his works' (Matthew 16:27), do not imagine that works in themselves merit either hell or the Kingdom. On the contrary, Christ rewards each man according to whether his works are done with faith or without faith in Himself; and He is not a dealer bound by contract, but God our Creator and Redeemer.

-- Saint Mark the Ascetic

Saint Bede the Venerable (On Saint John the Baptist)

As forerunner of our Lord’s birth, preaching and death, the blessed John showed in his struggle a goodness worthy of the sight of heaven. In the words of Scripture: Though in the sight of men he suffered torments, his hope is full of immortality. We justly commemorate the day of his birth with a joyful celebration, a day which he himself made festive for us through his suffering and which he adorned with the crimson splendour of his own blood. We do rightly revere his memory with joyful hearts, for he stamped with the seal of martyrdom the testimony which he delivered on behalf of our Lord.

-- Saint Bede the Venerable  from a homily on the martyrdom of Saint John the Baptist

Saint Augustine of Hippo

Conquer yourself and the world lies at your feet. 

-- Saint Augustine of Hippo