...we must first scrutinize thoroughly anything appearing in our hearts or any saying suggested to us. Has it come purified from the divine and heavenly fire of the Holy Spirit? Or does it lean toward Jewish superstition? Is its surface piety something which has come down from bloated worldly philosophy? We must examine this most carefully, doing as the apostle bids us: 'Do not believe in every spirit, but make sure to find out if spirits are from God'.
John CassianTrue spiritual knowledge has sometimes flourished most grandly in some who were without eloquence and almost illiterate. And this is very clearly shown by the case of the Apostles and many holy men, who did not spread themselves out with an empty show of leaves, but were bowed down by the weight of the true fruits of spiritual knowledge: of whom it is written in Acts: 'But when they saw the boldness of Peter and John, and perceived that they were ignorant and unlearned men, they were astonished' (Acts 4:13).
John CassianEverything we do, our every objective, must be undertaken for the sake of... purity of heart... we must practice the reading of the Scripture, together with all the other virtuous activities... to hold our hearts free of the harm of every dangerous passion and in order to rise step by step to the high point of love.
John CassianNo just man suffices unto himself for the winning of justification. The divine mercy must always hold out a hand to his footsteps as they falter and almost stumble, and this is so because the weakness of his free will may cause him to lose balance, and if he falls he may perish forever.
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