But he who endures to the end shall be saved. (Matthew 24:13)
Coptic Orthodox monk, Matthew the Poor offers these thoughts:
“Persistence in prayer and worship is one of the signs of effective faith. If faith represents the columns on which the temple of spiritual life stands, perseverance represents the stones by which the whole edifice is constructed. But to assess the value of the spirit of persistence in prayer, we should first consider the spirit of despondency.
Despondency is the folly of pride and stiffness of neck. The desperate man follows his own stubborn counsel and chooses the torment of everlasting hell. He does not wish to yield to God or accept from his hand the sweetness and the bitterness of this life. By doing so, he refuses the crown of eternal life.
The spirit of perseverance, on the other hand, is a sign of humility and surrender. The man who persists in prayer and worship does not think himself worthy of anything; his self is not dear to him. He persists in submission and obedience because he cannot cease from persistence and submission. On what else can he rely if his self is powerless and worthless in his eyes? ‘Jesus said to the twelve, “Do you also wish to go away?” Simon Peter answered him, “Lord, to whom shall we go? You have the words of eternal life”’ (John 6:67, 68).
The spirit of persistence springs from an inward conviction that life is but one single way that leads to the kingdom of heaven. Persistence in walking along that is then the only means of arrival, the only means of overcoming difficulties. Those who stop on the way, for whatever reason, have fallen in Satan’s snares: ‘Walk while you have the light, lest the darkness overtake you’ (Jn 12:35). That is, so long as you walk, the light attends you and leads you, but if you stop, darkness—that is, the enemy—will overtake you at once. Regression is a kind of miscarriage of the soul, a failure, and a fall into its deadly pride and its strange desire for perdition: ‘No one who puts his hand to the plough and looks back is fit for the kingdom of God’ (Luke 9:62).
It is really amazing that for those traveling along the way of prayer and worship, rest lies only in doubling their pace and increasing their struggle!” (Orthodox Prayer Life: The Interior Way, pg 164)