In English we have only one word to express all kinds of love; Greek has no fewer than four. Storgē (familial / friendship love), Erōs (romantic love), Philia (love with preferences, cultures and tastes), Agapē (unconditional love). And, the New Testament Bible was originally written in Greek.
Love is the greatest of all the virtues of the Christian Faith. The great reason why Christian thought fastened on agapē is that it demands the exercise of the whole man. Christian love must not only extend to our nearest and our dearest, our kith and kin, our friends and those who love us; Christian love must extend to the enemy, to all the world (for in such a way Christ loved the world and gave His life).
We speak about falling in love. That kind of love (which is erōs) is not an achievement; it is something which happens to us. There is no particular virtue in falling in love. But agapē is far more than that.
Agapē has to do with the mind: it is not simply an emotion which rises unbidden in our hearts; it is a principle by which we deliberately live. Agapē has supremely to do with the will. It is a conquest, a victory, and achievement. No one ever naturally loved his enemies. To love one’s enemies is a conquest of all our natural inclinations and emotions.
Bible says “God sends His rain on the good and the evil”. That is to say – no matter what a man is like, God seeks nothing but his highest good. Agapē is the spirit which says: “No matter what any man does to me, I will never seek to do harm to him; I will never set out for revenge; I will always seek nothing but his highest good.
That is to say, Christian Love, agapē, is unconquerable benevolence, invincible good will. It is not simply a wave of emotion; it is a deliberate conviction of the mind issuing in a deliberate policy of the life.
So we see beyond a doubt that the Christian Life has to be on the twin pillars of love of God and love of man.
William Barclay
Nice info