When tested by some trial you should try to find out not why or through whom it came, but only how to endure it gratefully, without distress or rancor.
Demons often transform themselves into angels of light and take the form of martyrs, and make it appear to us during sleep that we are in communication with them. Then, when we wake up, they plunge us into unholy joy and conceit. But you can detect their deceit by this very fact. For angels reveal torments, judgments and separations; and when we wake up we find that we are trembling and sad. As soon as we begin to believe the demons in dreams, then they make sport of us when we are awake too. He who believes in dreams is completely inexperienced. 'But he who distrusts all dreams is a wise man. Only believe dreams that warn you of torments and judgments. But if despair afflicts you, then such dreams are also from demons.
Now you become angry and fainthearted and grieved, thinking that the heavenly Father is slow in answering. But I tell you that this will also happen as you desire—it will definitely happen—but first it takes prayer with all your soul, and then you must wait. And when you have forgotten your request and have ceased asking for it, it will come to you as a reward for your patience and endurance. When you reach the verge of despair while praying and seeking, then the fulfillment of your request is near. Christ wants to heal some hidden passion within you, and this is why He delays in granting your request. If you obtain it sooner, when you demand it, your passion remains uncured within you. If you wait, you obtain your request and the cure of the passion. And then you rejoice exceedingly and give warm thanks to God Who arranges all things in wisdom and does everything for our benefit.
Knowing the exact nature of everything, God permits each person to be tested according to his strength. As St. Paul puts it: 'God is to be trusted not to let you be tried beyond your strength, but with the trial He will provide a way out, so that you are able to bear it' (1 Cor. 10:13).