Obedience to Christ in Our Weakness

The great saints knew their weaknesses and prayed in such a manner as, Do Thou, O Lord, extend Thy protecting hand over me, that I may not betray Thee this day.

Such folly, to the outsider, might seem this apparently weak devotion to Our Lord. Why, they might ask, do you claim to be His follower if you are so fickle a disciple, so fickle a friend, so half-hearted a servant?
Indeed, the question should cause us to consider the apparent contradiction: why do we call ourselves His friends if...