This is the 3167th most frequent Polish word.
religijnego
The Polish word "religijnego" means "religious" (genitive or accusative singular form, masculine or neuter).
In this sentence, 'religijnego' describes the type or focus of 'development', indicating it pertains to religion.
Czytałem esej na temat rozwoju religijnego.
I was reading an essay on religious development.
Here, 'religijne' (in an inflected form 'religijnym') modifies the noun 'significance', clarifying its nature or domain.
To jest pomnik o znaczeniu religijnym.
This is a monument of religious significance.
In this context, 'religijnych' (another inflected form) describes 'beliefs', emphasizing the character or foundation of these beliefs as religious.