It is good to love God for hope of reward, but it is better to love God for love's sake; and the prayer goes: O Lord, I do not want wealth nor children nor learning. If it be Thy will, I shall go from birth to birth. But grant me this, that I may love thee without the hope of reward 'love' unselfishly for love's sake.

The Complete Works of the Swami Vivekananda (ed. 1915)