The answer is in Romans 5 (and elsewhere); where you see that all men became sinners through Adam's sin and through Jesus' righteousness we all became righteous, even though in both instance, we did nothing to become either one.
The main issue also is the understanding of what God has used for the words sin and righteousness here in this chapter: they are nouns, not verbs. In other words, you are looking at existing in a state of sin vs a state of righteousness, not acts of sin vs acts of righteousness. And the words here are used from Greek which describe making an imprint with a piece of pottery or some type of mold that was pressed into clay to leave the exact likeness of the imprint behind. So, we, by Adam's one sin, were all imprinted with that sin such that we all existed in the eyes of God as sinners in the state of sin (or a prison of sin), and no matter how much righteousness we ever practiced it would make no difference - we'd still be sinners. Conversely, through Jesus' one act of righteousness (being the Lamb of God to take away our sins), we were all imprinted with His righteousness, now existing in a state of righteousness (still able to sin, but it has no effect on whether or not we are righteous - in the same way that a King making a bad decision does not remove him from being the King).
I mean, someone shout Hallelujah for what He has done for us! Glory to God! That's shouting grounds right there! And on top of that, we became authorized and empowered to walk in the Blessing of the Lord, just like Jesus!
