One has to distinguish between nitya (permanent) and anitya (impermanent), discard what ought not to be and take what ought to be. In fact the discarding of what ought not to be is more important.
In life itself, between what ought to be done and what ought not to be done, it may not matter if you don’t do what ought to be done; but by doing what ought not to be done one invites great trouble.
Take the common cold,, for instance. They say: ‘You should have rice mixed in mustard powder, but no icecream.’ One may not eat rice with mustard powder. But by having ice cream the cold intensifies and one ends up in fever.
Thus by eating prohibited food one experiences bad consequences immediately; on the other hand by eating the prescribed things do they immediately help? Not necessarily; they may or may not.
Again bathing in the river Cauvery, if you do it near the shore, it is good both physically and mentally. Those who don’t know swimming should not go into deep waters; if they do they will be drawn into the vortex of the flow.
A bath in the Cauvery may even be missed; even if it is not missed, though the mind gets refreshed a little, one does not observe any great improvement in health or spiritual merit. But if one goes into deeper waters the danger of the vortex swallowing you up is great.
Thus it always happens that in this play of MAyA in the world, the negative forces have usually more power. It therefore follows that once we have made an analysis of what is good for the spiritual ascent and what is bad, thereafter we should give first priority to the discarding of those which are bad.
Here, as I have said earlier, the ‘thereafter’ does not mean there is a strict ‘one after the other’ rule in SAdhanA. It happens that we have to exercise all the different steps of the SAdhanA together in a mixed fashion. At one stage some one of them becomes important or prominent and we usually talk of it as coming ‘later’ or ‘earlier’.