But note that I said this examination must be made upon the affections you have at the time, for it is not requisite that you should imagine to yourself such as may arise hereafter, since it is sufficient that we be faithful in present occurrences, according to the diversity of times, and since each season has quite enough labour and pain of its own.
Yet if you were desirous to exercise your heart in spiritual valour, by the representation of divers encounters and assaults, you might profitably do so, provided that after the acts of this imaginary valour which your heart may have made, you esteem not yourself more valiant: for the children of Ephraim, who did wonders with their bows and arrows in their warlike games at home, when it came indeed to the push upon the day of battle, turned their backs, and had not so much as the courage to lay their arrows on the string, or to face the points of those of their enemies. They have turned back in the day of battle. 
When therefore we practise this valour about future occurrences, or such as are only possible, if we find a good and faithful feeling we are to thank God for it, for this feeling is good as far as it goes: still we are to keep ourselves with humility between confidence and diffidence, hoping that by God's grace we should do, on occasion, that which we imagined, and still fearing that according to our ordinary misery we should perhaps do nothing and lose heart. But if the diffidence should become so excessive, that we should seem to ourselves to have neither force nor courage, and therefore feel a despair with regard to imaginary temptations, as though we were not in God's charity and grace, then in despite of our feeling of discouragement we must make a resolution of great fidelity in all that may occur up to the temptation which troubles us, hoping that when it comes, God will multiply his grace, redouble his succours, and afford us all necessary assistance; and while he gives us not the force for an imaginary and unnecessary war, he will give it us when it comes to the need. For as many in the assault have lost courage, so many have also lost fear, and have taken heart and resolution in the presence of danger and difficulty which without this they could never have done. And so, many of God's servants, representing to themselves absent temptations, have been affrighted at them even almost to the losing of courage, while when they saw them present, they behaved themselves courageously. Finally in those fears which arise from the representation of future assaults, when our heart seems to fail us, it is sufficient that we desire courage, and trust that God will bestow it upon us at the necessary time. Samson had not his strength always but we are told in the Scripture that the lion of the vines of Thamnatha, coming towards him, raging and roaring, the spirit of the Lord came upon him: that is, God gave him the movement of a new force and a new courage, and he tore the lion as he would have torn a kid in pieces.  And the same happened when he defeated the thousand Philistines, who thought they would have overthrown him in the field of Lechi. So, my dear Theotimus, it is not necessary for us to have always the feeling and movement of courage requisite to overcome the roaring lion which goeth about seeking whom he may devour: this might cause us vanity and presumption. It is sufficient that we have a good desire to fight valiantly, and a perfect confidence that the Holy Ghost will assist us with his helping hand, when occasion shall present itself.