If you are put into a dangerous position and you know how to save yourself from it, that very danger can become a source of pleasure for you.
In the material world, the living entity directs his will toward sense satisfaction because he has forgotten the spiritual field of willing. When the same will is directed toward satisfying the sense of the Supreme – Krishna – that is the eternal willing of the living entity.
In order to be happy, you must change the quality of your willing through purification. The purification process is bhakti – chanting and hearing the name, qualities and pastimes of the Lord. That purifies the will.
If we purify our existence, we can attain eternal happiness, spiritual bliss. Everyone is working hard for happiness, but how can happiness be attained in a diseased condition? The material disease is an impediment to happiness. This disease has to be cured.
A C Bhaktivedanta Swami Prabhupada
Source – Book – Beyond Illusion and Doubt