For in it the righteousness of God is revealed from faith for faith, as it is written, “The righteous shall live by faith.” (ESV)
At some point in each person's life there comes an understanding that we are flawed creatures. We recognize that there is a self-serving aspect of our nature that is willing to sabotage relationships with others to get what it demands. We will lie, steal and cheat one another in one form or another. Our flaws come completely clear when we come to an understanding of who God is.
Paul is a flawed creature who has good news concerning this dreadful nature that we all struggle with. He is speaking of the gospel. In the gospel the righteousness of God is revealed. This verse could better be translated "righteousness from God." Righteousness is the state of conforming perfectly to God's holy character and law. In our natural state this is an impossibility. We are flawed.
How can one obtain a righteousness that places them in perfect conformity to God's holy standard? Many people decide that they will take it upon themselves to live a holy life thinking that it will somehow attain to what God desires. They do their best to love others, give to the needy, practice acts of kindness to others. They achieve a good human standard. The problem is their standard falls short.
Paul begins to make the case in this verse that will be a theme for the entire book of Romans. The righteousness that we must have in order to be made right with God comes FROM God. We cannot create it. It is a gift that we receive by faith. This may be a new concept to some, but Paul will make the case that it has always been so. "The righteous shall live by faith."
Are you trying to be made righteous by your own efforts? I hope you are ready to give up soon. Being made right with God comes from placing our faith in his perfect Son and the sacrifice made on our behalf. The righteous shall live by faith.