In many ways the Lord tells us that we should fear nothing except sin, which takes away our friendship with God. Before any difficulty, before the environment, before an uncertain future... we should not fear, we should be strong and courageous, as befits children of God. A Christian cannot live in fear, but he must carry in his heart a holy fear of God, whom he otherwise loves madly.
Throughout the Gospel, "Christ repeats several times: Do not be afraid. And at the same time, together with these calls to strength, the exhortation resounds: Fear, fear rather him who is able to send body and soul to hell (Mt 10:28). We are called to strength and, at the same time, to the fear of God, and this should be a fear of love, a filial fear. And only when this fear penetrates our hearts can we be truly strong with the strength of the Apostles, of the martyrs, of the confessors.
Among the principal effects that the fear of God causes in the soul is detachment from created things and an interior attitude of vigilance to avoid the least occasion of sin. It leaves in the soul a particular sensitivity to detect all that can grieve the Holy Spirit.
The gift of fear is found at the root of humility, inasmuch as it gives the soul the awareness of its fragility and the need to have the will in faithful and loving submission to the infinite Majesty of God, always putting us in our place, without wanting to take God's place, without receiving honours that are for the glory of God. One of the manifestations of pride is ignorance of the fear of God.
Together with humility, the gift of fear of God has a singular affinity with the virtue of temperance, which leads to the moderate use of human things, subordinating them to the supernatural end. The most frequent root of sin is found precisely in the disordered search for sensible pleasures or material things, and there this gift is at work, purifying the heart and preserving it entirely for God.
The gift of fear is par excellence that of the struggle against sin. All the other gifts help him in this particular mission: the lights of the gifts of understanding and wisdom reveal to him the greatness of God and the true meaning of sin; the practical guidelines of the gift of counsel keep him in the admiration of God; the gift of strength sustains him in the unyielding struggle against evil.
This gift, which was infused with others in Baptism, increases to the extent that we are faithful to the graces given us by the Holy Spirit; and specifically, when we consider the greatness and majesty of God, when we make a deep examination of conscience, discovering and giving importance to our faults and sins. The holy fear of God will easily lead us to contrition, to repentance out of filial love: "love and fear of God. They are two strong castles, from which war is waged against the world and against the demons ".
The holy fear of God will gently lead us to a prudent distrust of ourselves, to flee quickly from the occasions of sin; and it will incline us to greater delicacy with God and with all that concerns Him. Let us ask the Holy Spirit to help us through this gift to sincerely acknowledge our faults and to truly grieve over them. May he make us react like the psalmist: rivers of tears have flowed from my eyes, because they have not observed your law. Let us ask him, with gentleness of soul, to bring to the surface the sense of sin.
https://www.hablarcondios.org/meditaciondiaria.aspx