Evidence is considered relevant when it covers all required items.
it is relevant if it covers
Purpose / Risk — collecting evidence for existing list of creditors is not relevant if risk of missing creditors
Test of Controls — evidence is not relevant if it doesnt cover evidend of TOC
Substantive Procedures — not relevant if substantive test not covered
Assertions — not relevant if it doesnt cover all assertions
i am assuming that you have seen video on core audit process and SA 500
Please give an example to relate all these points to that example to have more clarity