First in

Nothing can better dispose us for a third world war than the conviction that we are all doomed to fight anyway, that our enemies are well-armed gorillas too, and the only smart thing to do is to let them have it before they ambush us. In the chaotic atmosphere of a nation torn by race riots, deafened by the stridency of hate groups and of fanatics, it is understandable that readers may derive a kind of perverse comfort from this mythology.

Thomas Merton

Faith & Violence

Humility and loving one's enemies

The only sign of humility is the love of one’s enemies. When one loves his enemies, he says in effect that they are as worthy of life as he is, that the Kingdom of God does not depend upon the vindication of one’s own cause. When one loves his enemies, he has accepted the fact that he is not the center of the universe. He is willing to admit that the grace of God may be at work, even in his own behalf, in the resistance and rejection he encounters from others. By love of enemies and by this standard alone can the humility of Jesus be measured. The ‘humble of heart’ whom Jesus admires are those whose hearts have no hatred for their opponents.

Anthony PadovanoFree to Be Faithful

On a personal note, I'm note sure that the only sign of humility is to love one's enemies. Still I can concede the statement given the point Padovano's making. 

Wiser

Psalm 119:98. Thou through thy commandments hast made me wiser than mine enemies. 

The commands were his book, but God was his teacher. The letter can make us knowing, but only the divine Spirit can make us wise. Wisdom is knowledge put to practical use. Wisdom comes to us through obedience: "If any man will do his will he shall know of the doctrine." We learn not only from promise, and doctrine, and sacred history, but also from precept and command; in fact, from the commandments we gather the most practical wisdom and that which enables us best to cope with our adversaries. A holy life is the highest wisdom and the surest defence. Our enemies are renowned for subtlety, from the first father of them, the old serpent, down to the last cockatrice that has been hatched from the egg; and it would be vain for us to try to be a match with them in the craft and mystery of cunning, for the children of this world are in their generation wiser than the children of light. We must go to another school and learn of a different instructor, and then by uprightness we shall baffle fraud, by simple truth we shall vanquish deep laid scheming, and by open candour we shall defeat slander. A thoroughly straightforward man, devoid of all policy, is a terrible puzzle to diplomatists; they suspect him of a subtle duplicity through which they cannot see, while he, indifferent to their suspicions, holds on the even tenor of his way, and baffles all their arts. Yes, "honesty is the best policy." He who is taught of God has a practical wisdom such as malice cannot supply to the crafty; while harmless as a dove he also exhibits more than a serpent's wisdom.

 Charles Spurgeon, writing in The Treasury of David.

Putting His enemies under His footstool

From the additional notes to Charles Spurgeon's The Treasury of David, Psalm 110:

Verse 1. Make thine enemies thy footstool! This expression, that the conquest of Christ's enemies shall be but as the removing of a stool into its place, notes unto us two things: first, the easiness of God's victory over the enemies of Christ. They are before him as nothing, less than nothing, the drop of a bucket, the dust of the balance, a very little thing...Secondly, as this putting of Christ's enemies like a stool under the feet notes easiness, so also it notes order or beauty too. When Christ's enemies shall be under his foot, then there shall be a right order in things; then it shall indeed appear that God is a God of order, and therefore the day wherein that shall be done, is called "the times of the restitution of all things, "Ac 3:21. 

The putting of Christ's enemies under his feet is an act of justice; and of all others, justice is the most orderly virtue, that which keepeth beauty upon the face of a people, as consisting itself in symmetry and proportion. This putting of Christ's enemies as a stool under his feet, also denotes unto us two things in reference to Christ: first, his rest, and secondly, his triumph. To stand, in the Scripture phrase, denotes ministry, and to sit, rest; and there is no posture so easy as to sit with a stool under one's feet. Till Christ's enemies then be all under his feet, he is not fully in his rest. 

Furthermore, this "footstool" under Christ's feet, in reference to his enemies, denotes unto us four things. First, the extreme shame and confusion which they shall everlastingly suffer, the utter abasing and bringing down of all that exalteth itself against Christ. Secondly, hereby is noted the burden which wicked men must bear: the footstool beareth the weight of the body, so must the enemies of Christ bear the weight of his heavy and everlasting wrath upon their souls. Thirdly, herein is noted the relation which the just recompense of God bears unto the sins of ungodly men. Thus will Christ deal with his enemies at the last day. Here they trample upon Christ in his word, in his ways, in his members; they make the saints bow down for them to go over, and make them as the pavements on the ground; they tread under foot the blood of the covenant, and the sanctuary of the Lord, and put Christ to shame; but there their own measure shall be returned into their bosoms, they shall be constrained to confess as Adonibezek, "As I have done, so God hath requited me." 

Lastly, herein we may note the great power and wisdom of Christ in turning the malice and mischief of his enemies unto his own use and advantage; and so ordering wicked men that though they intend nothing but extirpation and ruin to his kingdom, yet they shall be useful unto him, and, against their own wills, serviceable to those glorious ends, in the accomplishing whereof he shall be admired by all those that believe. As in a great house there is necessary use of vessels of dishonour, destined unto sordid and mean, but yet daily, services: so in the great house of God, wicked men are his utensils and household instruments, as footstools and staves, and vessels wherein there is no pleasure, though of them there may be good use. 

Condensed from Edward Reynolds.

Love your enemies

Loving our enemies has become, in our time, the criterion of true Christian faith.  It may seem impossible, yet it can be done.  At no point is the inrush of divine grace so immediately and concretely perceptible as in those moments when we let go our hatred and relax into God's love.  No miracle is so awesome, so necessary, and so frequent.

Walter Wink
Engaging the Powers