"He will ... keep you firm to the end, so that you will be blameless on the day of our Lord Jesus Christ. God is faithful, who has called you into fellowship with his Son, Jesus Christ our Lord" (1 Corinthians 1:8-9).
Paul knew the correction he soon had to deliver in this letter, yet he stressed his confidence in the ultimate outcome of the situation based not on the Corinthians' righteousness or doctrinal understanding, but on the faithfulness of God. What he tells the Corinthian believers, and us, is that despite our problems God remains faithful to his purpose in us as long as are willing to continue to listen, learn and change as necessary.
Perhaps one of the most amazing things about this part of Paul's message to the problem- prone Corinthians is that it is almost identical to the message he had for the Thessalonians – a church he praises highly:
"... May your whole spirit, soul and body be kept blameless at the coming of our Lord Jesus Christ. The one who calls you is faithful, and he will do it" (1 Thessalonians 5:23-4).
The encouraging thing about these messages is that no matter where we may be on the "curve" of spiritual growth, we need not worry that we will not succeed as long as we continue to persevere. Paul's message to the Corinthians and Thessalonians is identical in this regard: Our faith need never waver, because God's faithfulness never does.