John Cassian : I ask, what could be said more clearly against that pernicious opinion and presumption of ours, by which we want to attribute everything that we do to our free will and to our own effort? "Do not say in your heart, when the Lord your God has destroyed them in your sight: Because of my righteousness the Lord has led me in to possess this land." Did he not express himself clearly to those whose souls' eyes are open and whose ears hear? Namely, when you have enjoyed a notable success in warring against the carnal vices and you see that you have been freed from their filthiness and from this world's way of life, you should not be puffed up with the success of the struggle and the victory and ascribe this to your own strength and wisdom, believing that you were able to obtain victory over evil spirits and carnal vices through your own efforts and application and free will. There is no doubt that you would never have been able to prevail over these if the Lord's help had not fortified and protected you. — CONFERENCE 5.15.3-4