To light a lamp, you need four elements – a container, oil, wick and a match box. If any one of them are missing, you cannot light the lamp. This lit lamp can, however, remove only the external darkness. How do you remove the darkness within the heart? It can be removed only by the Light of Wisdom (Jnana Jyoti). How to light the spiritual light, the light of wisdom? It needs four elements too. Detachment (Vairagya) is the container. Devotion (Bhakti) is the oil. One-pointed concentration (Ekagrata) is the wick. Knowledge of the Supreme Truth (Jnana) is the match stick. Without all the four, the light of Spiritual Wisdom cannot be got. Of the four, the primary prerequisite is the spirit of renunciation (Vairagya). Detachment is absence of attachment to the body. The ego-feeling, which makes one think of ‘I’ all the time, should be given up. Without this detachment, knowledge of scriptures is of no avail.