It's a cornerstone of their beliefs.

Meaning

The tradition is a fundamental aspect of their faith or worldview.

Examples

• John: Why is this ritual so important to them?
• Alice: <b>It's a cornerstone of their beliefs.</b> It's central to their spiritual practice.
• John: I see. It's deeply rooted in their faith.
• Alice: Precisely. <b>It's a cornerstone of their beliefs</b>, passed down through generations.