The hallmark of love is selfless sacrifice. Love seeks nothing from anyone. It bears no ill-will towards anyone. It is utterly selfless and pure.
Failing to understand the true nature of love, man yearns for it in various ways. Love has to be cherished with feelings of selflessness and sacrifice. In what is deemed as love in the world - whether it be maternal love, brotherly love, or friendship - there is an element of selfishness. Only God's Love is totally free from the taint of selfishness. Divine love reaches out even to the remotest being. It brings together those who are separate. It raises man from animality to divinity. It transforms gradually all forms of worldly love to Divine love. To experience this Divine love, men must be prepared to give up selfishness and self-interest. They must develop purity and steadfastness. With firm faith in the Divine, they must foster the love of God regardless of all obstacles and ordeals.
(SSS Vol XXIX - Chap 22)