The sustainment of The Universe, also known as Divine sustainment, or in wider discourse as theological sustainment, refers to a significant Astronic cosmological belief and the primary reaction provided by the Millettarian Tradition and Cometanism regarding the debate on the createdness of The Universe.

Divine sustainment maintains that The Universe, despite being infinite in its nature, and therefore without beginning or end, remains dependent upon The Divine. Thus, The Universe it is not divine by its nature for to hold a divine nature is to be without dependence of anything else in existence.

Essentially, the uncreatedness of The Universe is affirmed by Astronism to keep in alignment with the principles of its infinite nature. However, The Universe is considered to be sustained by and dependent upon The Divine, although the all-creativity of The Divine still remains affirmed. This triumvirate of ideas pertaining to The Universe's nature including its uncreatedness, divine sustainment, and divine omnicreativity is known as triadism. This forms an integral element to the overall Millettarian cosmology.