The Master Key to the laws of the universe is love.
Swami Sri Yukteswar wrote in his book, The Holy Science, of the effect of love on the human body: “When love, the heavenly gift of Nature, appears in the heart, it removes all causes of excitation from the system and cools it down to a perfectly normal state; and, invigorating the vital powers, expels all foreign matters — the germs of diseases — by natural ways (perspiration and so forth). It thereby makes man perfectly healthy in body and mind, and enables him to understand properly the guidance of Nature.”
Sri Yukteswar explained further the effects of love on human understanding: “When this love becomes developed in man, it makes him able to understand the real position of his own Self as well as of others surrounding him.”
Paramhansa Yogananda, Sri Yukteswar’s chief disciple, taught that the only way truly to understand others is by feeling deep compassion for them in one’s heart. Psychoanalysis is usually intellectual, and therefore provides only superficial insight into human nature. Deep insights are possible only with empathic love. That is why, when Paramhansa Yogananda was once asked, “What can take your place after you leave this world?” he replied with the sweetest smile, “When I am gone, only love can take my place.”
Love, that is to say, not only for God, but for God in others, in mankind, in all beings: this was his true meaning. As we contemplate the rays of Dwapara Yuga, it should be clear that love alone will help us fully to absorb their beneficial energies.