en_tn_lite_do_not_use/jas/01/26.md

thinks himself to be religious

"thinks he worships God correctly"

his tongue

Controlling one's tongue stands for controlling one's speech. AT: "what he says" (See: rc://en/ta/man/translate/figs-metonymy)

deceives

gets someone to believe something that is not true

his heart

Here "heart" refers to his belief or thoughts. AT: "himself" (See: rc://en/ta/man/translate/figs-metonymy)

his religion is worthless

"he worships God uselessly"