'religious sphere' is correct and can be used in written English.
For example, you might use it in a sentence like this: "The discussion of morality often extends into the religious sphere."
This religious sphere in our public life is very charged, and I want to disarm that".
"We have tried to keep it out of the religious sphere.
In the religious sphere, there is mobility, ecumenical understanding and blurry boundaries.
The Roman Catholic Church in Poland has played a social and cultural role far beyond the religious sphere.
The women at the fatwa hotline are attempting to redress a gender imbalance in the religious sphere.
His proposed solution -- taking government money out of the religious sphere -- would be far more complex than he may believe.
In preliterate societies he represents the life force of the tribe, in which worldly and spiritual or political and religious spheres are not distinguished.
In the economic and religious spheres, the clan did not exercise influence, but it did impose upon its members the collective duty of blood feud in the case of homicide between clans.
Alongside chiefs and shamans were ritualists dancers, singers, fire tenders, and others who were carefully trained in their crafts and who functioned intimately within the political, economic, and religious spheres of their communities.
He adapted ideas garnered from the then-current Romantic literatures in order to extend American libertarianism and individualism beyond the political and religious spheres to those of social and personal life.
"It is not just a military or security issue, it covers the intellectual, cultural, media and religious spheres," he added.
