'unchanging truth' is correct and can be used in written English.
You can use it to describe something that is true and will always remain true, for example: "The laws of gravity are an unchanging truth that we cannot escape."
A reference to an eternal, unchanging truth also renders the tense moot: "Dudley said the sun is hot".
That's not necessarily going to go over well with everyone, and he feels that he's sort of caught in a bind, that he's just telling the truth, the absolute, unchanging truth.
In all these novels, the hero's first impression is not adjusted by experience, leaving him sadder but wiser; it is the experience, an unchanging truth to which he must adjust.
From the time of the Enlightenment, most philosophers and scientists believed that there is an objective, universal, and unchanging truth about everything including science, ethics, religion, and politics—and that human reason is powerful enough to discover this truth.
The goal of Samayika is to achieve a feeling of perfect calmness and to understand the unchanging truth of the self.
And of course we also have to carry around the heavy baggage of all of those old stories we think we know are some unchanging truth.
He has been lambasting Pope Francis for sowing "confusion among the faithful" by refusing to defend "the unchanging truths of Catholicism".
Another item in the platform declared that "homosexual behavior is contrary to the fundamental unchanging truths that have been ordained by God".
Don't ask: Homosexuality is a chosen behavior that is contrary to the fundamental unchanging truths that have been ordained by God in the Bible, recognized by our nation's founders, and shared by the majority of Texans.
In New York City's restaurant firmament, where establishments ceaselessly open and close, where fortunes are made and lost overnight, and where chefs can go as hot and as cold as the soup, there are few unchanging truths.
These are men who, by the sheer ingenuity of their brains, discovered universal and unchanging truths and expressed them in equations that were poetry by numbers, powerful, elegant and pure.It fell to Kenneth Appel and Wolfgang Haken, his partner in crime for that is how many mathematicians saw them to be the first to disrupt that image, by bringing in computers to help.
