That’s what John Lennon was singing about and it is true, all we need is love. But do we really know what love is? Love is a word that is sung about in songs, written in poems, talked about a lot and it is something many people long for one way or the other, mostly in form of a partner.
True esoteric work and knowledge can only be grasped and applied by a certain type of human being and another type does not posses this ability in his/her current life cycle. One type has a soul, the other one is soul-less, so to speak. There is no difference on the outside and in terms of personality, but the inner life is vastly different.