Being filled with something is a metaphor that represents being characterized by it or by habitually doing it. Possible meanings of "fruit of righteousness" are that 1) it is a metaphor that represents righteous behavior. Alternate translation: "you also will habitually do what is righteous because Jesus Christ enables you" or 2) it is a metaphor that represents good deeds as a result of being righteous. Alternate translation: "you also will habitually do good works because Jesus makes you righteous" (See: [[rc://en/ta/man/translate/figs-metaphor]])
Possible meanings are 1) "Then other people will see how you honor God" or 2) "Then people will praise and give honor to God because of the good things they see you do." These alternate translations would require a new sentence.