[Psa. 5:9 says], “Their throats are like open graves [i.e., they are foul-mouthed]. They have spoken deceitfully.” [Psa. 90:3 says], “There is snake venom under their lips [i.e., their words are deadly].”
All of us [Jews] also once lived among such people, fulfilling the improper cravings of our physical being and doing what our bodies and minds desired. In this natural [unconverted] state we were deserving of [God’s] wrath, just like the rest [of mankind].
He was once useless to me, but is now useful to [both] you and me. [Note: Since the name Onesimus means “useful,” it appears Paul is making an intentional play on the word].