Yes, religion is an abstract noun; religion is a form of belief.

Rusula is a word from the Islamic faith. And is the word that describes the belief in prophethood and is closely related to Kutubu'llah which is a belief in the books of Allah.

Ecological systems theory proposed by Urie Bronfenbrenner and dynamic systems theory are examples of developmental theories that are not stage theories. They emphasize the interactions between individuals and their environment, as well as the continuous and dynamic nature of development over time.

Belief systems are what people believe about the world and/or religion. It is the organization and structure of the way a person thinks the world works.

Islam is not against these theories.