No Christian believing rightly in God should ever be off his guard. He should always be on the look-out for temptation, so that when it comes he will not be surprised or disturbed, but will gladly endure the toil and affliction it causes, and so will understand what he is saying when he chants with the prophet: 'Prove me, O Lord, and try me' (Ps. 26:2 LXX). For the prophet did not say, 'Thy correction has destroyed me,' but, 'it has upheld me to the end' (Ps. 18:35 LXX).
Sear your loins by abstaining from food, and prove your heart by controlling your speech, and you will succeed in bringing the desiring and incensive powers of your soul into the service of what is noble and good.
Also in another place it shows that the angels are the ministers of the saints. For when Elijah was on the mountain and foreigners were rising up against him, his servant said, 'Many are coming against us and we are all alone.' Then Elijah answered, 'Do you not see the armies and multitudes of angels with us surrounding us to aid us?' (2 Kg. 6:15). You see how the Master and the multitude of angels are standing by the side of their servants.
My son, says Scripture, if you come to serve the Lord, prepare your soul for trial, set you heart straight, and patiently endure (Eccles. 2:1-2). And elsewhere it is said: Accept everything that comes as good, knowing that nothing occurs without God willing it. Thus the soul that wishes to do God's will must strive above all to acquire patient endurance and hope. For one of the tricks of the devil is to make us listless at times of affliction, so that we give up our hope in the Lord. God never allows a soul that hopes in Him to be so oppressed by trials that it is put to utter confusion. As St. Paul writes: God is to be trusted not to let us be tried beyond our strength, but with the trial He will provide a way out, so that we are able to bear it (I Cor. 10:13). The devil harasses the soul not as much as he wants but as much as God allows him to. Men know what burden may be placed on a mule, what on a donkey, and what on a camel, and load each beast accordingly; and the potter knows how long he must leave the pots in the fire, so that they are not cracked by staying in it too long or rendered useless by being taken out of it before they are properly fired. If human understanding extends this far, must not God be much more aware, infinitely more aware, of the degree of trial it is right to impose on each soul, so that it become tried and true, fit for the kingdom of heaven?