Consider our LORD’S DESIGN IN THIS PARABLE—“Men ought always to pray and not to faint” [Luke 18:1]. But can men pray always? There was a sect in the earlier days of Christianity who were foolish enough to read the passage literally, and to attempt praying without ceasing by continual repetition of prayers. They, of course, separated themselves from all worldly concerns, and in order to fulfill one duty of life, neglected every other! Such madmen might well expect to reap the due reward of their follies. Happily there is no need in this age for us to duplicate such an error! There is far more necessity to cry out against those who under the pretense of praying always, have no settled time for prayer at all, and so run to the opposite extreme.
Our Lord meant, by saying men ought always to pray, that they ought to be always in the spirit of prayer—always ready to pray; like the old knights, always in warfare—not always on their steeds dashing forward with their lances in position to unhorse an adversary, but always wearing their weapons where they could readily reach them, and always ready to encounter wounds or death for the sake of the cause which they championed.
– C. H. Spurgeon, “The Importunate Widow”