Beyond this covering there is another nature. That is spiritual nature. We get this information from the Vedic literature. Paras tasmāt tu bhāvo 'nyo 'vyakto 'vyaktāt sanātanaḥ (BG 8.20). And we living entities, we are the marginal energy. That means if we like, we can live in this material nature—if we like, we can transfer ourselves to the spiritual nature.
The spiritual nature is . . . it is not in . . . what is called, incompatible. Compatible. You can adjust yourself in the spiritual nature, but you cannot adjust yourself in the material nature. Therefore material nature, however you can make your plans for becoming happy, it will be frustrated. Because you do not . . . you cannot adjust yourself with this material nature.
Just like this body. This body is a product of this material nature. Now, however you can take care of this body, however you may go on making this body very strong and stout, still, you cannot maintain it. It will be finished today or tomorrow or a hundred years after. You cannot protect it. This is material nature. But I have got the tendency to keep my body fit, strong and eternal. That is my tendency. People are taking so much exercise just to become very strong and stout. But nature will not allow you. However stout and strong you may be, you have to die. You have to give up this body.