The Greek word aneko

Found only in Eph. 5:4; Col. 3:18; Phile. 8, the Greek verb “aneko,” is often translated with words like “convenient,” “fitting,” or “proper.”

There is to be “proper behavior” among God’s people (Eph. 5:4) because they are in a saved relationship with Christ (Col. 3:18).  Paul’s use of this word in Phile. 8 seems to also include a legal sense.