A Universal Problem

What then? Are we Jews any better off? No, not at all. For we have already charged that all, both Jews and Greeks, are under sin, as it is written:
  “None is righteous, no, not one;
no one understands;
no one seeks for God.
All have turned aside; together they have become worthless;
no one does good,
not even one.”
“Their throat is an open grave;
they use their tongues to deceive.”
“The venom of asps is under their lips.”
“Their mouth is full of curses and bitterness.”
“Their feet are swift to shed blood;
in their paths are ruin and misery,
and the way of peace they have not known.”
“There is no fear of God before their eyes.”  (Romans 3:9-18 ESV)
Paul tells us in Romans 3 that our sin is a UNIVERSAL problem... "None is righteous - not even one." He pulls together the Psalms to let us know that it is an age old problem, not just a problem for Paul's time, but before his time; and as we know from our own lives, long after... He addresses the Romans (and us) through carefully selected Psalms to show us that every area of life is infected by our sin.
First: He focuses on the heart (what we are) (vv. 10-12) - we've turned from God

Next: He focuses on the tongue (what we say) (vv. 13-14) - we are hostile to truth and our words show it...
Lastly: He focuses on the feet (what we do) (vv. 15-18)  - our actions...the way of death and violence, misery, and ruin our words bring to others. 
A self seeking heart leads to a bitter tongue, and a bitter tongue leads strife in the world around us.  As Christians we are not to engage in bitter words that create strife, and when we do, we need to repent.
Who and what we are revealed in what we say and what we do... Only God's grace can save us.  It's the only remedy from what we are..Trust in Christ's payment for your sin today.