Purity of Heart is to Will One Thing
"Another says 'I have not the strength to risk all." Again evasion, an evasion by the aid of the word "all." For the Good is quite capable of reckoning and computing its demand in relation to the strength that this man has. And what is more, if he will venutre in all sincerity, then he will certainly receive strength enough in the act of decision...And in a spiritual sense, a person is only really out at sea who is willing to do all, irrespective of whether he is the highest or the least."
"So then, go with God to God, continually take that one step more, that single step that even you, who cannot move a limb, are still able to take; that single step, that even the prisoner, who has lost his freedom, even the one in chains, whose feet are not free, is still able to take: and you are committed to the Good."