Peter was first given the keys, but then he was allowed to fall into the sin of denying Christ; and so his pride was humbled by his fall. Do not be surprised, then, if after receiving the keys of spiritual knowledge you fall into various evil thoughts. Glorify our Lord, for He alone is wise: through setbacks of this kind He restrains the presumption that we tend to feel because of our advance in the knowledge of God. Trials and temptations are the reins whereby God in His providence restrains our human arrogance.
Not one of us can boast of having acquired humility: our actions, the whole of our life, prove the contrary. And where there is a lack of humility, pride is always present. Where light is wanting, darkness reigns.
You are, I am sure, aware that for you penitence is now no longer limited to disclosing your sins to your confessor, but that you must now bear your sins in mind always, until your heart nearly breaks with their ugly load; and would break, were it not for your firm faith in the mercy of our Lord.
Bear this in mind: the Christian life is an unending spiritual fight. The wily enemy cleverly uses snares and arrows without number. Before some of us he spreads the lure of worldliness, the outer pride of pomp and circumstance, the cruder lusts-the lusts of the flesh. But those of us who are not attracted by any of this he leads up on to the peaks of subtler prides. Having got us there-to the high country of self-esteem-he causes a dark mist, the mist of the subtlest prides, to enshroud our intellect. Then he leads us, his blinded slaves, away from God, without our even suspecting it. Mark this too: it is not very hard for the simple sinner to come to hate his foul life and, leaving it, to fling himself on the mercy of God; but it is very hard for the subtler sinner-the self-sufficient one-to let a ray of divine love pierce the leather jacket of his self-righteousness... Humility is the only weapon that wards off all attacks, but it is difficult to fashion, and the art of using it is often misunderstood, particularly by those who lead an active, worldly life.
God smiles on the compassionate heart. Every time a beggar knocks at your door, try to perceive Christ Himself under the humble disguise. Would you, under any circumstances, let Christ knock in vain? The moral qualities of the individual beggar have nothing to do with it; that is Christ's concern, not yours. Who are you to judge your brother? Christ is using the beggar’s hand and mouth to test your compassion of Himself. Will you fail Him?
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.
Whenever we enter the church and draw near to the heavenly mysteries, we ought to approach with all humility and fear, both because of the presence of the angelic powers and out of the reverence due to the sacred oblation; for as the Angels are said to have stood by the Lord's body when it lay in the tomb, so we must believe that they are present in the celebration of the Mysteries of His most sacred Body at the time of consecration.
A haughty person is not aware of his faults, or a humble person of his good qualities. An evil ignorance blinds the first, an ignorance pleasing to God blinds the second.
In answer to your question as to what constitutes a happy life, whether splendor, fame and wealth, or a quiet, peaceful, family life, I will say that I agree with the latter, but will add the following: A life lived in humility and with an irreproachable conscience brings peace, tranquility, and true happiness. But wealth, honor, glory and exalted position often serve as the cause of a multitude of sins, and such happiness is not one on which to rely.
Do all in your power not to fall, for the strong athlete should not fall. But if you do fall, get up again at once and continue the contest. Even if you fall a thousand times because of the withdrawal of God's grace, rise up again each time, and keep on doing this until the day of your death. For it is written, 'If a righteous man falls down seven times' - that is, repeatedly throughout his life - 'seven times shall he rise again' [Prov. 24:16].
Suppose you have ordered yourself not to eat fish; you will find that the enemy continually makes you long to eat it. You are filled with an uncontrollable desire for the thing that is forbidden. In this way you can see how Adam's fall typifies what happens to all of us. Because he was told not to eat from a particular tree, he felt irresistibly attracted to the one thing that was forbidden him.
It is more serious to lose hope than to sin. The traitor Judas was a defeatist, inexperienced in spiritual warfare; as a result he was reduced to despair by the enemy's onslaught, and he went and hanged himself. Peter, on the other hand, was a firm rock: although brought down by a terrible fall, yet because of his experience in spiritual warfare he was not broken by despair, but leaping up he shed bitter tears from a contrite and humiliated heart. And as soon as our enemy saw them, he recoiled as if his eyes had been burnt by searing flames, and he took flight...
In the beginning, there is struggle and a lot of work for those who come near to God. But after that, there is indescribable joy. It is just like building a fire: at first it's smoky and your eyes water, but later you get the desired result. Thus we ought to light the divine fire in ourselves with tears and effort.
The joint prayer of husband and wife is a great force. That may be one of the reasons why the enemy is trying to get both of you to break this excellent habit. [This is] one more temptation which God permits so that you should learn to overcome it and come out of the testing stronger than before!