The Guardian Angel often helped Santa Faustina, that's what he did and can do for us too

Saint Faustina has the grace to see her guardian angel several times. He describes him as a luminous and radiant figure, a modest and serene gaze, with a ray of fire coming out of his forehead. It is a discreet presence, which speaks little, acts and above all never detaches itself from her. The Saint tells several episodes about it and I like to bring back some of them: for example, once in response to the question asked to Jesus "for whom to pray", her guardian angel appears to her who orders her to follow him and leads her to purgatory. Saint Faustina says: "My guardian angel did not abandon me for a moment" (Quad. I), proof of the fact that our angels are always close to us even if we do not see them. On another occasion, traveling to Warsaw, her guardian angel makes herself visible and keeps her company. In another circumstance he recommends that she pray for a soul.
Sister Faustina lives with her guardian angel in intimate relationship, prays and often invokes receiving help and support from him. For example, it tells of a night when, annoyed by evil spirits, she wakes up and begins "quietly" to pray to her guardian angel. Or again, in spiritual retreats pray "Our Lady, the guardian angel and patron saints".
Well, according to Christian devotion, we all have a guardian angel assigned to us by God since our birth, who is always close to us and will accompany us to death. The existence of angels is certainly a tangible reality, not demonstrable by human means, but a reality of faith. In the Catechism of the Catholic Church we read: “The existence of angels - A reality of faith. The existence of spiritless, incorporeal beings, which Sacred Scripture habitually calls angels, is a truth of faith. The testimony of Scripture is as clear as the unanimity of Tradition (n. 328). As purely spiritual creatures, they have intelligence and will: they are personal and immortal creatures. They outperform all visible creatures. The splendor of their glory testifies (n. 330) ".
In all sincerity, I believe it is beautiful and reassuring to believe in their existence: to be sure of never being alone, to know that there is a faithful advisor next to us who does not scream and does not order us, but "whispers" advice in full respect of the "Style" of God. We have a help beside us that surely intervenes in our favor and providentially in various moments of our life, even if too often we do not notice it: I think everyone lives sooner or later situations of danger or more or less serious needs, in which inexplicably something happens at the right time and in the right place to help us: well, for us Christians it is certainly not a question of chance, it is not about luck, but it is about providential interventions of God who probably makes use of his heavenly army . I think it is right to awaken our consciences, to go back to being a little children, why not, and to have the holy fear of acting, remembering that we are not alone, but that we have a witness before God of our "pranks", of the actions that we know to be wrong. Santa Faustina says:
“Oh, how little people think of this, that such a guest always has with him and at the same time a witness of everything! Sinners, remember that you have a witness for your actions! " (Quad. II, 630). However, I do not believe that the guardian angel is a judge: I rather believe he is really our best friend, and that "holy fear" should simply be our desire not to disrespect him with our sins, and our desire that he approve of our choices and actions.