Question
Why do we need Yamalokam?
Answer
The answer to this question is linked to the concept of residual karma. This residual karma idea and what happens to evil-doers is explained in Brahma Sutra.
But of others (i.e. those who have not performed sacrifices etc.) the ascent is to the abode of Yama, and after having experienced (the results of their evil works) the descent (to the earth again takes place). On account of such a passage (for the evil-doer) being declared by the Sruti. (Brahma Sutra Sankara Bhasya 3.1.13)
The Sruti passage referred to in the above shloka is:
The Hereafter never reveals itself to a person devoid of discrimination, heedless, and perplexed by the delusion of wealth. "This world alone exists," he thinks," and there is no other." Again and again he comes under my sway. (Yama speaks in Katha Upanishad I.2.6)
It is clear that if you do bad deeds that you end up in Yama Loka. However, there are two perplexing questions here. Does the person who descends to earth from Yama loka return with any Karma (i.e. is the Karma of the evil-doer after serving his term in Yama loka zero?)? What decides that a person will after death be immediately reborn in earth or return to earth after serving a time in Yama loka? These two questions are actually linked. The answer to this question is given in Brahma Sutra:
On the exhaustion of (good) work (the soul) with residual Karma (descends to this earth), as is known from the Sruti amd Smriti, along the path (it) went by (from here) and differently too. (Brahma Sutra Sankara Bhasya 3.1.8)
The above Sutra says that what is exhausted in heaven is only that specific Karma which gave the soul a birth in lower heaven, but on the exhaustion of this Karma the remaining Karma, good and bad, brings it back to earth. While this Sutra talks of heaven and good deed, it also applies to Yama Loka and bad deeds. Let me explain the idea by a concrete example. Let us suppose that a dead person has a list of 10 karmas with goodness values (1, -3, 4, 5, -100, 4, 3, 2, 5, 8) where the minus sign stands for evil deeds. What Brahma Sutra Sankara Bhasya 3.1.8 is saying is that this person will go to Yama Loka only for that extremely evil deed of goodness value -100. After he has exhausted the bad effect due to the -100 Karma, he can then go back to earth with the residual karma (1, -3, 4,5,4,3,2,5,8). The idea is that only extremely evil or good deeds lead a man to Yama loka or to lower heavens. All minor good and bad karmas are served on the earth plane.
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