the.com/secularism

means The principle of keeping religion separate from government and public institutions so no single faith controls the state.

from Coined in the mid-1800s by English writer George Jacob Holyoake, who built it from the Latin saeculum, meaning 'the age' or 'this present world' — the same root that gives us 'secular.' Holyoake wanted a word for an ethical stance focused on human welfare in this life, without relying on religious doctrine or requiring belief or disbelief in any god. The term later broadened into its modern political sense: the separation of religious authority from the machinery of the state.