The Importance of Yagna in Ancient Times

In ancient times, the laws of nature were not properly understood. The rains came because you prayed to God, and not just God in general, but the specific gods that govern the rain. With that in mind, you can understand how important Yagna was in ancient times. If you want the rains to come on time, if you're a farmer with your crops planted, you better worship the right deities and make the right offerings into that ritual fire to propitiate.