Unless humility and love, simplicity and goodness regulate our prayer, this prayer - or, rather, this pretence of prayer - cannot profit us at all. And this applies not only to prayer, but to every labor and hardship undertaken for the sake of virtue.
'If you do not feel like praying, you have to force yourself,' the Elder said. 'The Holy Fathers say that prayer with force is higher than prayer unforced. You do not want to, but force yourself. The Kingdom of Heaven is taken by force.'
The one who prays ought never to halt his movement of sublime ascent toward God. For just as we should understand the ascent 'from strength to strength' as the progress in the practice of the virtues, 'from glory to glory' (2 Cor. 3:18) as the advance in the spiritual knowledge of contemplation, and the transfer from the letter of sacred writing to its spirit, so in the same way the one who is settled in the place of prayer should lift his mind from human matters and the attention of the soul to more divine realities.
When said with pain, the prayer gives birth to mourning. Mourning brings tears. Tears in turn give birth to purer prayer. For tears like a fragrant myrrh wash away the filth, and thus the inbreathing of God is cleansed, which like a dove is confined within four walls, as if made of the four elements.... And then, as soon as the walls break down and collapse, the dove immediately flies to the Father whence it came.
A great effort and much toil are needed in prayer before we can reach a state in which our mind is no longer troubled, and so attain the inward heaven of the heart where Christ dwells. As St. Paul says, 'Do you not realize that Christ dwells within you, unless you are worthless?' (cf. 2 Cor. 13:5).
Prayer demands that the mind should be pure of all thought and should admit nothing not belonging to prayer, even if it were good in itself. As if inspired by God the mind should withdraw from all things and hold its converse with Him alone.
The enemy of our salvation especially strives to draw our heart and mind away from God when we are about to serve Him, and endeavours to adulterously attach our heart to something irrelevant. Be always, every moment, with God, especially when you pray to Him. If you are inconstant, you will fall away from life, and will cast yourself into sorrow and straitness.
Let us then not lose heart, nor be slothful or timid in prayer. Even if we have been brought down to the depths of evil, prayer can speedily draw us back.
You describe how bitterly you regret the inefficacy of your prayers. Beware: to wish for consolation or revelation in prayer is a sure sign of pride. Pray humbly, in perfect simplicity, seeking salvation only through forgiveness, & having faith that God will extend to you His mercy - as He did to the publican.
The head of every good striving and the pinnacle of all corrections is to persevere in prayer, by which we may ever obtain, through entreaty of God, all the other virtues as well. By prayer those who are worthy partake of the sanctity of God and spiritual activity and the union of the mind with the Lord in unutterable love. He who constantly forces himself to endure in prayer is roused by spiritual love to Divine fervor and flaming desire towards God, and he receives, according to his measure, the grace of spiritual, sanctifying perfection.