RobH_en_tn/rom/04/14.md

heirs

The people to whom God has made promises are spoken of as if they were to inherit property and wealth from a family member. (See: rc://en/ta/man/translate/figs-metaphor)

if those who live by the law are to be the heirs

Here "live by the law" refers to obeying the law. Alternate translation: "if those who obey the law are the ones who will inherit the earth" (See: rc://en/ta/man/translate/figs-explicit)

faith is made empty, and the promise is void

"faith has no value, and the promise is meaningless"