What does 1 Corinthians 1:8 mean?

This is one of Scripture's truly great promises about what it means to be in Christ. Paul has been giving thanks to God for all the amazing things He has done for the Christians in Corinth. Everything he has mentioned is true of all Christians.

Reading these words, it's important to notice that nothing Paul has written mentions anything the Corinthians themselves have done. God has done it all, in and for them, as a free gift because of their faith in Christ. The rest of Paul's letter will show that as individuals and as a church, these believers in Corinth struggle with major spiritual problems. They are indulging in attitudes and actions that are sinful. Still, Paul writes the words of this verse to them and to all who are in Christ. God will not stop giving the Corinthians His good gifts. He will not stop sustaining them, keeping them going, holding them together. They will remain guiltless or blameless in His eyes all the way to the return of Christ on the day of the Lord.

How is this possible? Why would God do this? God's grace to us is rightly called "amazing." For those who come to Him by faith, God receives Christ's death as payment for our sins and gives us credit for Christ's righteous, sinless life on earth (Romans 5:6–11). That's why, instead of dreading the return of Christ, Christians can wait for it with eager hopefulness (Galatians 5:5; Romans 8:19–25).