The beginning of the fight against hatred, the basic Christian answer to hatred is not the commandment to love, but what must necessarily come before in order to make the commandment bearable and comprehensible. It is a prior commandment, to believe. The root of Christian love is not the will to love, but the faith that one is loved. The faith that one is loved by God. That faith that one is loved by God although unworthy—or, rather, irrespective of one's worth!
In the true Christian vision of God's love, the idea of worthiness loses its significance. Revelation of the mercy of God makes the whole problem of worthiness something almost laughable: the discovery that worthiness is of no special consequence (since no one could ever, by himself, be strictly worthy to be loved with such a love) is a true liberation of the spirit. And until this discovery is made, until this liberation has been brought about by the divine mercy, man is imprisoned in hate. (New Seeds of Contemplation by Thomas Merton, pp. 76-77)
We love him, because he first loved us. (1 John 4:19)