What does Romans 3:9-18 mean?

9 What then? are we better than they? No, in no wise: for we have before proved both Jews and Gentiles, that they are all under sin; 10 As it is written, There is none righteous, no, not one: 11 There is none that understandeth, there is none that seeketh after God. 12 They are all gone out of the way, they are together become unprofitable; there is none that doeth good, no, not one. 13 Their throat is an open sepulchre; with their tongues they have used deceit; the poison of asps is under their lips: 14 Whose mouth is full of cursing and bitterness: 15 Their feet are swift to shed blood: 16 Destruction and misery are in their ways: 17 And the way of peace have they not known: 18 There is no fear of God before their eyes. (Romans 3:9-18 KJV)

All Have Sinned

Having removed these objections, Paul revives his assertion of the general guilt of mankind (Ro 3:9-18). “Are we better than they? No, in no way.” Jews and Gentiles alike are under sin, under guilt and bondage, enslaved and condemned (Ps 38:4). This charge he had already proved, and here he further illustrates it by scriptures that describe the universal corruption of man (Ps 14:1-3; Ps 53:1-3). God himself, who once looked upon creation and found it very good, now looks and finds it very bad (Ge 6:5).

There is none righteous, not one. None understand, none seek after God (Ro 3:10-11). All have become unprofitable; none do good, no not one (Eccl 7:20). They are all gone out of the way; mankind is in apostasy.

Their words are cruel, deceitful, and bitter. Their throat is an open grave, the poison of asps under their lips, their mouth full of cursing (Ro 3:13-14; Ps 5:9; Jas 3:8-9). Their ways are violent: their feet swift to shed blood, destruction and misery in their paths, the way of peace unknown (Ro 3:15-17; Isa 59:7-8).

The root of all is this: There is no fear of God before their eyes (Ro 3:18; Ps 36:1). Where no fear of God is, no good can be expected. The fear of God restrains us (Neh 5:15); without it, prayer is restrained (Job 15:4), and ruin follows quickly. Thus is the universal depravity of mankind, so that we may say, O Adam, what have you done? God made man upright, but he has sought out many inventions.