Nicene and Post-Nicene Fathers, Ser. II, Vol. XI:
The Works of John Cassian.: Chapter XV. From whom we can learn the way of perfection.

Chapter XV.

From whom we can learn the way of perfection.

And so, if we wish in very deed and truth to attain to the crown of virtues, we ought to listen to those teachers and guides who, not dreaming with pompous declamations, but learning by act and experience, are able to teach us as well, and direct us likewise, and show us the road by which we may arrive at it by a most sure pathway; and who also testify that they have themselves reached it by faith rather than by any merits of their efforts. And further, the purity of heart that they have acquired has taught them this above all; viz., to recognize more and more that they are burdened with sin (for their compunction for their faults increases day by day in proportion as their purity of soul advances), and to sigh continually from the bottom of their heart because they see that they cannot possibly avoid the spots and blemishes of those faults which are ingrained in them through the countless triflings of the thoughts. And therefore they declared that they looked for the reward of the future life, not from the merits of their works, but from the mercy of the Lord, taking no credit to themselves for their great circumspection of heart in comparison with others, since they ascribed this not to their own exertions, but to divine grace; and without flattering themselves on account of the carelessness of those who are cold, and worse than they themselves are, they rather aimed at a lasting humility by fixing their gaze on those whom they knew to be really free from sin and already in the enjoyment of eternal bliss in the kingdom of heaven, and so by this consideration they avoided the downfall of pride, and at the same time always saw both what they were aiming at and what they had to grieve over: as they knew that they could not attain that purity of heart for which they yearned while weighed down by the burden of the flesh.