There are two ways in which the world can end, either by its own transience or by our transcending it as well as abiding in it.

1. Transience (saṃsāra): 

The Purāṇas etc. see the universe as involved in an immense cycle – the cycle of Brahma, which lasts an astronomical length of time, starting with the emission of the universe and ending with its dissolution only to start a new cycle. According to this view we are in the fourth and last stage, the Kālī-yuga.

Abhinavagupta accepts this cycle of time and describes it in his Tantrāloka. He also associates it with breath so that each cycle of breathing (exhalation/inhalation) is a reliving of the cycle of night and day, of the phases of the moon, the revolution of the sun, and of the cycle of Brahma.

This idea is reflected to some degree in modern physics which generally holds to the ‘big-bang’ and considers the possibility of the ‘big crunch’.

2. Transcendence/immanence:

However, the whole purpose of Kashmir Shaivism, as of Indian spirituality, is to escape the cycle of rebirths.

For the Vedānta, the escape consists in seeing the universe as essentially an illusion (māyā) without substance. The only reality is Brahman (not to be confused with the cycle of Brahma). The person who remains caught up in the world of transience will pass with it and will be reborn in it.

The solution of the Greeks was to develop the idea of the soul, which persists despite the cycle of rebirths. For Plato etc., this is the doctrine of the ‘transmigration of souls’ (metempsychosis). 

In Kashmir Shaivism, the liberated individuals – liberated-while-living (jīvanmukta) – see the whole universe as an expression of their Self, for they know they are ‘I am’.  Whether the world lasts or does not last, no matter – all the aspects of the universe, its coming and going, are just manifestations of their Self. This world is the ‘play’ (līlā) of Siva, something they enjoy doing but are not forced to do. They both transcend this universe – since it is an expression of their Self – and is immanent, for the same reason:  it is a manifestation of their Self and is identified with their Self. It is their body. The jīvanmukta rises above the universe for they are liberated (unlike those human beings who are totally immersed in the world and cannot see themselves apart from it); and live their daily life happily and with total commitment to work, friendships etc. for they are living. The world has ended since they are not tied to it. The world continues since they see it as themselves and love it as themselves.

This attitude of being ‘liberated-while-living’ is the goal of Kashmir Shaivism and fits in very well with the character of the Christian who is ‘in this world, but not of it’ (Gospel of John, chapter 17).