The only essence in this world is prem or love. It is eternal, infinite and un-decaying. Physical love is passion or infatuation (moha). Universal love is only Divine love. cosmic love and universal love are synonymous terms. God is love. Love is God. Selfishness, greed, egoism, vanity, pride and hatred contract the heart and stand in the way of developing universal love.
Develop universal love gradually through selfless service, satsang with great souls, prayer, recitation of guru mantra, etc,. When the heart is contracted through selfishness in the beginning, man loves only his wife, children, a few friends and relatives. As he evolves, he loves the people of his own district, then the people of his own province. Later on, he develops love for men of his own country. Eventually he begins to love other people of different countries. in the long run he begins to love all. He develops universal love. All the barriers are broken now. Heart is expanded infinitely.