Havan Puja Handbook Now you can find out about every step of puja – a scientific process of rebirth and renewal the gives you control over your destiny. Swami Ram takes you through a detailed ceremony Havan Puja or AGNIHOTRA is a detailed ceremony to the Fire God – The destroyer of diseases, bacteria, and all illusionary forms. Fire destroys all material but nothing spiritual. So also it must destroy earthly karmas but not spiritual karmas.