...we should realize that there are three sources for our thoughts - God, the devil, and ourselves.
John CassianNo other virtue makes man more equal to the angels, than the imitation of their way of life.
John CassianWhen the soul is solidly rooted in... peacefulness, when it is freed of the bonds of every carnal urge, when the unshaking thrust of the heart is toward the one supreme Good, then the words of the apostle will be fulfilled. 'Pray without ceasing,' he said (I Thes. 5:17). 'In every place lift up pure hands, with no anger and no rivalry' (I Tim 2:8). Sensibility is, so to speak, absorbed by this purity. It is reshaped in the likeness of the spiritual and the angelic so that all its dealings, all its activity will be prayer, utterly pure, utterly without tarnish.
John Cassian... when death has been brought upon a saint, we ought not to think that an evil has happened to him but a thing indifferent; which is an evil to a wicked man, while to the good it is rest and freedom from evils. 'For death is rest to a man whose way is hidden' (Job 3:23 LXX). And so a good man does not suffer any loss from it.
John CassianWe are often indifferent to our brethren who are distressed or upset, on the grounds that they are in this state through no fault of ours. The Doctor of souls, however, wishing to root out the soul's excuses from the heart, tells us to leave our gift and to be reconciled not only if we happen to be upset by our brother, but also if he is upset by us, whether justly or unjustly; only when we have healed the breach through our apology should we offer our gift.
John CassianGod is not only to be known in His blessed and incomprehensible being, for this is something which is reserved for His saints in the age to come. He is also known from the grandeur and beauty of His creatures, from His providence which governs the world day by day, from His righteousness and from wonders which He shows to His saints in each generation.
John Cassian