Romans 3:10-18-There is no one righteous, not even one; there is no one who understands; there is no one who seeks God.  All have turned away, they have together become worthless; there is no one who does good, not even one.  Their throats are open graves; their tongues practice deceit.  The poison of vipers is on their lips.  Their mouths are full of cursing and bitterness.  Their feet are swift to shed blood; ruin and misery mark their ways, and the way of peace they do not know.  There is no fear of God before their eyes.  

The reason Paul makes such a big deal about us being sinners is that we cannot understand, value, desire the righteousness of God without knowing the depths of our lack and need of this righteousness.  Paul’s goal is to prove the universal unrighteousness of humanity.  First he looks at the Gentiles:

Romans 1:18-31- For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of humans, who by their unrighteousness suppress the truth.  For what can be known about God is plain to them, because God has shown it to them.  For his invisible attributes, namely, his eternal power and divine nature, have been clearly perceived, ever since the creation of the world, in the things that have been made.  So they are without excuse.  For although they knew God, they did not honor him as God or give thanks to him, but they became futile in their thinking, and their foolish hearts were darkened.  Claiming to be wise, they became fools, and exchanged the glory of the immortal God for images resembling mortal man and birds and animals and creeping things.  Therefore God gave them up in the lusts of their hearts to impurity, to the dishonoring of their bodies among themselves, because they exchanged the truth about God for a lie and worshiped and served the creatures rather than the Creator, who is blessed forever!  Amen.  For this reason God gave them up to dishonorable passions.  For their women exchanged natural relations for those contrary to nature, and the men likewise gave up natural relations with women and were consumed with passion for one another, men committing shameless acts with men and receiving in themselves the due penalty for their error.  Furthermore, just as they did not think it worthwhile to retain the knowledge of God, so God gave them over to a depraved mind, so that they do what ought not to be done.  They have become filled with every kind of wickedness, evil, greed and depravity.  They are full of envy, murder, strife, deceit and malice.  They are gossips, slanderers, God-haters, insolent, arrogant and boastful; they invent ways of doing evil; they disobey their parents; they have no understanding, no fidelity, no love, no mercy.  

Then he looked at the Jews:

Romans 2:1-3:8- You, therefore, have no excuse, you who pass judgment on someone else, for at whatever point you judge another, you are condemning yourself, because you who pass judgment do the same things.  Now we know that God’s judgment against those who do such things is based on truth.  So when you, a mere human being, pass judgment on them and yet do the same things, do you think you will escape God’s judgment?  Or do you show contempt for the riches of his kindness, forbearance and patience, not realizing that God’s kindness is intended to lead you to repentance.  But because of your stubbornness and your unrepentant heart, you are storing up wrath against yourself for the day of God’s wrath, when his righteous judgment will be revealed.  God will repay each person according to what they have done.  To those who by persistence in doing good seek glory, honor and immortality, he will give eternal life.  But to those who are self-seeking and who reject the truth and follow evil, there will be wrath and anger.  There will be trouble and distress for every human being who does evil: first for the Jew, then for the Gentile; but glory, honor and peace for everyone who does good: first for the Jew, then for the Gentile.  For God does not show favoritism.