General:
* Universal: Implies applicability to all cases.
* Omnipresent: Means being present everywhere at once, suggesting it's always relevant.
* Invariable: Means not changing or capable of changing, highlighting consistency.
* Absolute: Means complete and perfect, suggesting no exceptions.
More Specific:
* Valid: Means logically sound and acceptable.
* Applicable: Means relevant and fitting to the situation.
* Appropriate: Means suitable and fitting for the circumstances.
* Pertinent: Means relevant and directly connected to the topic.
Figurative:
* Eternal: Suggests something that lasts forever and is always true.
* Immutable: Means unchanging and unchangeable, highlighting permanence.
* Timeless: Implies something that transcends time and remains relevant forever.
The best word will depend on the specific context of your writing. Consider the specific meaning you want to convey and choose the word that best fits your purpose.