The word ‘yajna’ means sacrifice; that is the primary purpose of the yajna. You sacrifice riches, comfort, power (all that promotes the ego) and merge in the Infinite. That is the attainment and the end. Yajnas are useful because they support the ideal of sacrifice, and condemn acquisition. They emphasise discipline, rather than distraction. They insist on the concentration of the mind, the tongue and the hand on Godhead. Cynics count the bags of grain and the kilograms of ghee, and ask for more bags and kilograms of contentment and happiness in return! The effects of yajna on the character and the consciousness cannot be measured or weighed in metres or grams. It is immeasurable, though actual and experienceable. The grain and ghee offered in the sacred fire to the accompaniment of Vedic formulae give thousandfold returns; they will cleanse and strengthen the atmosphere all over the world.