Does God expect Christians to never fall into sin?

Les explains that God doesn't expect us never to fall, and when we do, He's right there ready to pick us up and put us on our way. That, he says, is not the concept most people have of the grace of God, but it is what grace is. Les connects this to Paul in verse 21: I do not frustrate the grace of God. Paul refuses to fly in the face of grace by saying he has to do this because the law says so. Today believers are not under the law but under grace. Grace is God's attribute capable of pouring out undeserved favor and mercy on sinners, all because of the love poured out at the cross—love epitomized, an act of love for sinners, undeserving. If righteousness comes by the law, by legalism, then Christ is dead in vain.