There is no strength

As a matter of fact, it is not difficult to do something which is even quite good, as the pagans also did. But let someone intentionally define a course for himself of a continuous doing of good, and define the order of it according to what is indicated in the word of God—and this not for one month or for a year, but for one’s whole life—and place as a rule to remain in this order unwaveringly; and then, when he remains faithful to this, let him boast of his own power. But without this it is better to close one’s mouth. How many cases there have been in the past and in the present of a self-trusting beginning and building of a Christian life! And they have all ended and continue to end in nothing. A man builds a little in his new order of life—and then throws it away. How can it be otherwise? There is no strength. It is characteristic only of the eternal power of God to support us unchanging in our disposition in the midst of the unceasing waves of temporal changes. Therefore one must be filled abundantly with this power; one must ask for and receive it in order—and it will raise us up and draw us out of the great agitation of temporal life.

St Theophan the Recluse. The Path to Salvation, 32–33.