“Since all the strength by which our enemies are overcome is born in us from disbelief in ourselves and from trust in God, it is necessary for you, my brother, to acquire exact knowledge of this, in order always to have this strength and to preserve it with the help of God. Know then, and never forget, that neither all our capacities and good features, whether natural or acquired, nor all the gifts freely given us, nor the knowledge of all the Scriptures, nor the fact that we have for long worked for God and have acquired experience in these labours, nor all this together will enable us to do God’s will rightly, if at every good deed pleasing to God, which we are about to undertake, at every affliction we wish to avoid, at every cross we have to bear according to God’s will, if, I say, on all these and similar occasions a special divine help does not inspire our heart and does not give us strength to accomplish it, as the Lord said: ‘Without me ye can do nothing’ (John xv. 5). So for the duration of our life, every day and at every moment, we must keep unchanged in our heart the feeling, conviction and disposition, that on no occasion can we allow ourselves to think of relying on ourselves and trusting ourselves.
As regards trust in God, I will add the following to what I have said in the third chapter: know that nothing is easier for God than to give you victory over your enemies, whether they be few or many, whether they be old and strong or new and weak. Yet He has His own time and order for everything. Therefore if a soul be overburdened with sins, if it be guilty of all the crimes in the world, if it be defiled beyond imagination;—if, at the same time, to the extent of its desire and strength, it uses every means and endeavour to become free of sin and turn to the path of good, but cannot get stable in anything right, however small, and, on the contrary, sinks ever deeper and deeper into evil; even if it is all that, it must not weaken in its trust of God or fall away from Him. It must not abandon its spiritual weapons and strivings but must fight and fight, struggling with itself and with its enemies with all its courage and untiring efforts. For know and under- stand, that in this unseen war all are losers except a man who never ceases to struggle and keep his trust in God; for God never abandons those who fight in His armies, although at times He/ lets them suffer wounds. So fight, everyone, and do not give ground; for the whole thing is in this unceasing struggle. /God is always ready with remedies for those struck down by the enemies and with help for overcoming them, which He sends to His warriors in due time, if they seek
Him and firmly hope in Him. At some’ hour when they least expect it they will see their proud enemies vanish, as is written: ‘ The mighty men of Babylon have forborn to fight’ (Jer. li. 30).”
Source: St. Theophan the Recluse, Unseen Warfare, Chapter 6, p. 10