en_tn_lite_do_not_use/eph/04/18.md

They are darkened in their understanding, alienated from the life of God

Here "darkened in their understanding" is a metaphor that means not to be able to understand the truth. And "alienated from the life of God" is a metaphor that means to not have the life that God gives. Alternate translation: "They do not understand what is true, and they do not have the life that God gives to people" (See: rc://en/ta/man/jit/figs-metaphor)

because of the ignorance that is in them

"because they refuse to learn what is true"

because of the hardness of their hearts

Here "hearts" is a metonym for people's minds. The phrase "hardness of their hearts" is a metaphor that means "stubbornness." Alternate translation: "because they are stubborn" or "because they refuse to listen to God" (See: rc://en/ta/man/jit/figs-metonymy and rc://en/ta/man/jit/figs-metaphor)