Paul hastily wrote off humanity, unlike the Psalmist who knew better

 

Let God be true, but every man a liar.

-- Romans 3:4

I said in my haste, All men are liars.

-- Psalm 116:11 

I said in my ecstasy: Every man is a liar

Hell is empty, and all the devils are here.

KJV Psalm 116.11:  I said in my haste, All men are liars.  

RSV Psalm 116.11:  I said in my consternation, "Men are all a vain hope."

LXX Psalm 115.2:   ἐγὼ εἶπα ἐν τῇ ἐκστάσει μου πᾶς ἄνθρωπος ψεύστης