We might say "you" or, probably preferably, "we." For example, "We don't always do what we know that we should."
Paul names sin as what is keeping us from doing what we know is right. We can see that doing the right thing is the right thing to do, but we are tempted to do something else. But, we don't need to despair. Paul reminds us that rescue is available to us.
Ronald Allen & Clark Williamson, in Preaching the Letters, discuss Paul's understanding of Sin:
Sin for Paul is not individual sins or the piling up of all of them into some big thing called "Sin" with a capital S, ... a power that governs the world in the old age in which we still live, in spite of the fact that in Jesus Christ we have a foretaste of God's righteousness, .... Paul not only does not express guilt for sinning--"it is no longer I that do it"--he does not admit responsibility for it, at least not so far as to be made guilty for it. Sin is a power in which individuals, groups and nations can become ensnared, like a fish caught in a net. It is our weakness that sin exploits.
They then add:
What we should not do then is wallow in guilt feelings. We should do what Paul did--sing praises to God through Jesus Christ for the magnificent gift of grace (v25).
"Thanks be to God through Jesus Christ our Lord!"