Why do Hindus believe in doing ‘Sraddha ’ (annual death anniversary) of ancestors, even though they believe in the concept of
First, there is no guarantee that one will take birth right after one dies. There is usually an undefined time lapse between births because the next upadhi may not yet be ready.
Secondly, The offerings you offer to ancestors reach them in a form suitable to their current upadhi. For example, if the person has taken birth as a snake, your offering gets transformed into air and reaches the manes. So on and so forth. If they are in swarga, it will reach them as amRta. The accompanying mantra has this power. It is similar to money being deposited in one city and being withdrawn in another city and even in another country in that country's currency. This analogy is given by Sringeri Jagadguru Sri Bharati Tirtha Mahaswami.
One must never shirk one's responsibility towards one's pitR's
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