"unbelieving" is a perfectly acceptable and usable word in written English.
You can use it to indicate a lack of belief, usually in the context of religious beliefs, or when someone is skeptical of something. Example Sentence: The unbelieving man refused to accept that the power of the divine could heal him.
He has brought us to live apart from the clamor and lies of the unbelieving.
"His father?" he asked, unbelieving.
It was my fifth such Easter, but I was still anxious, aware that everyone would be looking to see what unbelieving had done to me.
Our fear is bearable – even pleasing – because it is generally unbelieving.
The shave is not so much not close enough as not a shave at all, instead a kind of endless passing of my hand unbelieving through a hologram.
Each time, he was told, with barely a glance at his documents, "Sorry, you don't qualify," and each time he emerged from the air-conditioned cool of the Consulate into the harsh sunlight stunned and unbelieving.
The bad reputation of Abu Bakr al-Razi (850-925 circas as a "heterodox" and "unbelieving" philosopher of Medieval Islam seems to have generally influenced most of the Medieval Jewish authors, as it appears in particular in Maimonides.
It believed that striking at a universally accepted global enemy, the US, would lead to the destruction of "hypocrite" unbelieving regimes across the Muslim world in the short term and, eventually, the creation of a new ill-defined and utopian religious rule.
Jacques Berlinerblau, the author of "Thumpin' It: The Use and Abuse of the Bible in Today's Presidential Politics", reckons that unbelieving Americans will feel excluded by lines such as "Freedom requires religion just as religion requires freedom".
In unbelieving, lapsed Britain, God is a polite puzzle more than an everyday challenge.
