Our prayer reflects our attitude towards God. He who is careless of salvation has a different attitude toward God from him who has abandoned sin and is zealous for virtue but has not yet entered within himself and works for the Lord only outwardly. Finally, he who has entered within and carries the Lord within himself, standing before Him, has yet another attitude. The first man is negligent in prayer, just as he is negligent in life, and he prays in church and at home merely according to the established custom, without attention or feeling. The second man reads many prayers and goes often to church, trying at the same time to keep his attention from wandering and to experience feelings in accordance with the prayers which are read, although he is seldom successful. The third man, wholly concentrated within, stands with his mind before God, and prays to Him in his heart without distraction, without long verbal prayers, even when standing for a long time at prayer in his home or in church.... Every prayer must come from the heart and any other prayer is no prayer at all. Prayer-book prayers, your own prayers and very short prayers, all must issue forth from the heart to God, seen before you.
Wherever we are and whatever our circumstances, the enemy always tries to prevent us from actively responding to the call. Pray for help. For help that you may never fail to respond. And beware lest, having received help and having done the right deed because of it, you should grow proud and acquire the habit of condemning others, in the secret chambers of your heart. Beware! For this would make all the fruits of your good works wither.
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 beginning of wisdom is the fear of the Lord. For where there is fear, there the commandments are kept; where the commandments are kept, there is the flesh purified—that cloud which envelops the soul and prevents it from seeing clearly the Divine ray; where the flesh is purified, there light springs forth, and the shining of the light fulfils desire above all desires.
When praying, endeavor by every means to feel in your heart the truth and the power of the words of the prayer; feed yourself upon them as upon an imperishable food; water your heart with them as with a dew; and warm yourself by them as by means of a beneficial fire.
Do not pray for the fulfillment of your wishes, for they may not accord with the will of God. But pray as you have been taught, saying: 'Thy will be done in me' (Luke 22.42). Always entreat Him in this way, that His will be done. For He desires what is good and profitable for you, whereas you do not always ask for this. Often when I have prayed, I have asked for what I thought was good, and persisted in my petition, stupidly importuning the will of God, and not leaving it to Him to arrange things as He knows is best for me, But when I have obtained what I asked for, I have been very sorry that I did not ask for the will of God to be done, because the thing turned out not to be as I thought.
Before the war begins, seek out your ally; before you fall ill, seek out your physician; and before grievous things come upon you, pray, and in the time of your tribulations you will find Him, and He will listen to you.