Here, each of these quotes contains the word 'fear', and has to do with some aspect of it. I think reading it one begins to gain an idea of what kind of fear is good, and when it is not. Eventually one could gain an idea of how a saint feels about it, and then one knows how one should approach the matter properly, and pray God to be able to think, feel, and live so.
'No one can love God consciously in his heart unless he has first feared Him with all his heart. Through the action of fear the soul is purified and, as it were, made malleable and so it becomes awakened to the action of love. No one, however, can come to fear God completely in the way described, unless he first transcends all worldly cares; for when the intellect reaches a state of deep stillness and detachment, then the fear of God begins to trouble it, purifying it with full perception from all gross and cloddish density, and thereby bringing it to a great love for God's goodness. . . Fear and love are found together only in the righteous who achieve virtue through the energy of the Holy Spirit in them. For this reason Holy Scripture says in one place: "O fear the Lord, all you who are His saints," (Ps. 34:9) and in another: "O love the Lord, all you who are His saints." (Ps. 31:23) From this we see clearly that the righteous, who are still in the process of being purified, are characterized both by fear and by a moderate measure of love; perfect love, on the other hand, is found only in those who have already been purified and in whom there is no longer any thought of fear, but rather a constant burning and binding of the soul to God through the energy of the Holy Spirit. As it is written, "My soul is bound to Thee: Thy right hand has upheld me." (Ps. 63:8. LXX)'
St. Diadochos of Photiki
'If wounds in the body have been neglected and left unattended, they do not react to medicine when the doctors apply it to them; but if they have first been cleansed, then they respond to the action of the medicine and so are quickly healed. In the same way, if the soul is neglected and wholly covered with the leprosy of self-indulgence, it cannot experience the fear of God, however persistently it is warned of the terror and power of God's judgment. When, however, through great attentiveness the soul begins to be purified, it also begins to experience the fear of God as a life-giving medicine which, through the reproaches it arouses in the conscience, burns the soul in the fire of dispassion. After this the soul is gradually cleansed until it is completely purified; its love increases as its fear diminishes, until it attains perfect love, in which there is no fear but only the complete dispassion which is energized by the glory of God. So let us rejoice endlessly in our fear of God and in the love which is the fulfilling of the law of perfection in Christ (cf. Rom. 13:10).'
St. Diadochos of Photiki
'Blessed the one who always keeps the memory of God in himself, he will be wholly like an Angel from heaven upon earth, ministering to the Lord with fear and love.'
St. Ephrem of Syria
'Blessed the one who draws near with fear and trembling and dread to the spotless Mysteries of the Saviour and has realized that he has received in himself eternal life.'
St. Ephrem of Syria
'Blessed the one who is fired by the fear of God, ever having in himself the fervour of the Holy Spirit, and who has burned up the thorns and thistles of the thoughts.'
St. Ephrem of Syria
'Blessed the one who rebukes his neighbour with fear of God and has not deceived his soul, fearing each day the iron rod of the great Shepherd.'
St. Ephrem of Syria
'Blessed the one who loves truth continually and has not lent his mouth as an instrument of impiety by lying, for he fears the commandment about idle speech.'
St. Ephrem of Syria
'Blessed the one who keeps in mind the fire that came down on Mount Sinai and the sounds of the trumpets and Moses standing there with fear and trembling and who does not neglect his own salvation.'
St. Ephrem of Syria
'I am sent to you to confute, not to embrace your heresy. The Catholic religion is the faith of all ages, I fear not death. . . Pardon my enemies, O Lord: blinded by passion they know not what they do. Lord Jesus, have mercy on me. Mary, Mother of God, succor me!'
St. Fidelis of Sigmaringen, upon his death
'Truly it is a blessed thing to love on earth as we hope to love in Heaven, and to begin that friendship here which is to endure for ever there. I am not now speaking of simple charity, a love due to all mankind, but of that spiritual friendship which binds souls together, leading them to share devotions and spiritual interests, so as to have but one mind between them. . . There are two sayings in Holy Scripture on which all Christian friendship should be built: - that of the Wise Man, "Whoso feareth the Lord shall direct his friendship aright;" and that of St. James, "The friendship of the world is enmity with God."'
St. Francis de Sales
'Before giving birth to St. Augustine, St. Monica offered him repeatedly to God's Glory, as he himself tells us; and it is a good lesson for Christian women how to offer the fruit of their womb to God, Who accepts the free oblations of loving hearts, and promotes the desires of such faithful mothers: witness Samuel, St. Thomas Aquinas, St. Andrea di Fiesole, and others. St. Bernard's mother, worthy of such a son, was wont to take her new-born babes in her arms to offer them to Jesus Christ, thenceforward loving them with a reverential love, as a sacred deposit from God; and so entirely was her offering accepted, that all her seven children became Saints. And when children begin to use their reason, fathers and mothers should take great pains to fill their hearts with the fear of God. This the good Queen Blanche did most earnestly by St. Louis, her son: witness her oft-repeated words, "My son, I would sooner see you die than guilty of a mortal sin;" words which sank so deeply into the saintly monarch's heart, that he himself said there was no day on which they did not recur to his mind, and strengthen him in treading God's ways.'
St. Francis de Sales
'We ought to employ ourselves in compassionating our loving Mother in Her grief over the sufferings of Her Son. In return, She will comfort and console us and at the hour of death, will show us Her sweet face and deliver us from all fear. She will take us under Her protecting mantle, and with the sword that transpierced Her most pure Heart, She will defend us against our enemy.'
St. Gabriel Possenti of the Sorrowful Mother
'If one fears men much he will never do anything great for God: all that one does for God arouses persecution.'
St. Ignatius of Loyola
'It is not enough to say you desire to serve our Lord: you must declare and acknowledge fearlessly that you are His servant and His slave, and that you would die rather than abandon His service.'
St. Ignatius of Loyola
'We should not fear much the insults of this life, which are confined to words; were they all united they could not hurt a hair of our head.'
St. Ignatius of Loyola
'They who at the outset count up too strictly the difficulties and accidents of an undertaking, or who yield to fear too easily, will never accomplish anything great.'
St. Ignatius of Loyola
'Do not put faith in constant happiness, and fear most when all smiles upon you.'
St. Ignatius of Loyola
'The devil sometimes removes all fear from you, only to make you fall; he exaggerates in order to discourage you, and in everything he only seeks your ruin.'
St. Ignatius of Loyola
'If some shameful thought is sown in your heart as you are sitting in your cell, watch out. Resist the evil, so that it does not gain control over you. Make every effort to call God to mind, for He is looking at you, and whatever you are thinking in your heart is plainly visible to Him. Say to your soul: "If you are afraid of sinners like yourself seeing your sins, how much more should you be afraid of God who notes everything?" As a result of this warning the fear of God will be revealed in your soul, and if you cleave to Him you will not be shaken by the passions; for it is written:
"They that trust in the Lord shall be as Mount Zion; he that dwells in Jerusalem shall never be shaken" (Ps. 125:1. LXX). Whatever you are doing, remember that God sees all your thoughts, and then you will never sin. To Him be glory through all the ages. Amen.'
St. Isaiah the Solitary
'Let us stand firm in the fear of God, rigorously practicing the virtues and not giving our conscience cause to stumble. In the fear of God let us keep our attention fixed within ourselves, until our conscience achieves its freedom. Then there will be a union between it and us, and thereafter it will be our guardian, showing us each thing that we must uproot. But if we do not obey our conscience, it will abandon us and we shall fall into the hands of our enemies, who will never let us go. This is what our Lord taught us when He said:
"Come to an agreement with your adversary quickly while you are with him in the road, lest he hand you over to the judge, and the judge deliver you to the officer and you are cast into prison (Matt. 5:25)." The conscience is called an 'adversary' because it opposes us when we wish to carry out the desires of our flesh; and if we do not listen to our conscience, it delivers us into the hands of our enemies.'
St. Isaiah the Solitary
'Alas, my dear brethren, how greatly we should fear, lest we do not recognise our temptations! And we shall never recognise them if we do not ask God to allow us to do so.'
St. Jean Marie Baptiste Vianney, the Cure of Ars
'A good Christian watches continually, sword in hand. The devil can do nothing against him, for he resists him like a warrior in full armour; he does not fear him, because he has rejected from his heart all that is impure. Bad Christians are idle and lazy, and stand hanging their heads; and you see how they give way at the first assault: the devil does what he pleases with them; he presents pleasures to them, he makes them taste pleasure, and then, to drown the cries of their conscience, he whispers to them in a gentle voice, "You will sin no more." And when the occasion presents itself, they fall again, and more easily than the first time. If they go to confession he makes them ashamed, they speak only in half-words, they lower their voice, they explain away their sins, and, what is more miserable, they perhaps conceal some. The good Christian, on the contrary, groans and weeps over his sins, and reaches the tribunal of Penance already half justified.'
St. Jean Marie Baptiste Vianney, the Cure of Ars
'If a priest is determined not to lose his soul, so soon as any disorder arises in the parish he must trample under foot all human considerations as well as the fear of the contempt and hatred of his people. He must not allow anything to bar his way in the discharge of duty, even where he is certain of being murdered on coming down from the pulpit. A pastor who wants to do his duty must keep his sword in hand at all times.'
St. Jean Marie Baptiste Vianney, the Cure of Ars
'I invite you: make haste. You have made light of my entreaties; perhaps you will listen to my reproaches. Effeminate soldier! What are you doing under the paternal roof? Though your mother tear her hair and rend her garments, though your father stand on the threshold and forbid your departure, you must be deaf to the voice of nature, and hasten with unmoistened eye to enlist under the banner of Christ; love for God and fear of hell easily breaks all chains.'
St. Jerome
'He who walks along a precipice, although he may not fall over, yet he trembles and often falls through that very fear. Even so, he who flies not far from sin, but keeps near to it, lives in continual fear, and often falls.'
St. John Chrysostom
'Let us hasten with joy and trepidation to the noble contest and with no fear of our enemies. They are themselves unseen but they can look at the appearance of our soul. If they are really to see our spirits bowed down by fear, then indeed they will make a harsher sally against us, knowing how much we tremble. Let us courageously arm ourselves against them. No one goes to battle against a plucky fighter.'
St. John Climacus
'How can you venture to live without fear, seeing that you must appear before God to give an account of your lightest words and thoughts?'
St. John of the Cross
'The first degree of humility is the fear of God, which we should constantly have before our eyes.'
St. Louis de Blois
'He is well, because he was a worthy priest; but it would have been better for him if he had had a firmer faith in the virtue of the Passion of Christ, and if he had had during his life a greater fear of Purgatory!'
St. Lydwine of Schiedam
'How is it you do not fear to touch the work of God; do you not fear the chastisement His justice prepares for you?'
St. Lydwine of Schiedam
'I think that this fear which Our Lord makes you feel is the result of His very great love for you; for seeing that your love for Him is not powerful enough to make you do good and avoid evil, He mingles fear with love, that the two together may make you do what He desires of you.'
St. Margaret Mary Alacoque
'He only asks of you abandonment and perfect submission. Nothing displeases Him so much as your uneasiness and despondency. What do you fear? Is He not powerful enough to support you? Why, then, are you so reserved with Him? Let Him act!'
St. Margaret Mary Alacoque
'Know that He wishes more love than fear from you. Therefore, abandon yourself to His love, and let Him act in you, with you and for you, according to His desire and good pleasure.'
St. Margaret Mary Alacoque
'Should you feel yourself overwhelmed by fear, cast yourself into the abyss of the unshaken confidence of the Sacred Heart, and there your fear will give place to love. If you find yourself frail and weak, lapsing into faults at every moment, go to the Sacred Heart and draw from It the strength which will invigorate and revive you.'
St. Margaret Mary Alacoque
'Strive ever to have a loving and filial fear, which will lead you to do good and avoid evil, rejecting all other fears, for they only come from the spirit of darkness.'
St. Margaret Mary Alacoque
'Deeper spiritual knowledge helps the hard-hearted man: for unless he has fear, he refuses to accept the labor of repentance.'
St. Mark the Ascetic
'Acts of kindness and generosity are spoilt by self-esteem, meanness and pleasure, unless these have first been destroyed by fear of God.'
St. Mark the Ascetic
'He who has come to know the truth does not oppose the afflictions that befall him, for he knows that they lead him to the fear of God.'
St. Mark the Ascetic
'He who with fear of God admonishes or corrects a man who has sinned, gains the virtue that is opposite to that sin. But he who reproaches him out of rancor and ill will becomes subject to a similar passion, according to the spiritual law.'
St. Mark the Ascetic
'The fear of God compels us to fight against evil; and when we fight against evil, the grace of God destroys it.'
St. Mark the Ascetic
'We must know how to confide. There is the fear of God and the fear of a Judas. Too much fear makes one labour without love, and too much confidence prevents from considering the danger which we must overcome.'
St. Padre Pio
'We must fear that terrible beast, self love; it is a serpent with seven heads which intrudes itself everywhere. There is nothing which frightens me more and puts me more on my guard against the impulses of my heart, lest they be prompted by it.'
St. Paul of the Cross
'I may add that, though you think that you are rejoicing in your trials, you should not make any account of this disposition, because the devil could thereby easily fill you with vanity. It is better to fear and to distrust one's self, having in view only the will of God.'
St. Paul of the Cross
'Keep interior peace at every cost; pay no attention to fears or scruples. Experience will teach you that those vain fears of sin, etc., which I call veritable follies, ought to disappear in the fire of love.'
St. Paul of the Cross
'O my God, my Father! I hope in Thee, I love Thee. Infernal spirit, begone from me! No more scruples, no more doubts, no more fears! May the love of my Jesus live in me! May the love of Jesus reign forever!"'
St. Paul of the Cross
'If our salvation depended only on ourselves, we should have much to fear; but as it is in the hands of God, we can tranquilly repose in Him.'
St. Paul of the Cross
. . .
Well there is more there than this, but it is a beginning. . .