1 Thessalonians 5:23-24...
May the God of peace himself sanctify you completely. May your whole spirit, soul, and body be preserved blameless at the coming of our Lord Jesus Christ. He who calls you is faithful, who will also do it. (WEB)
This is a wonderful prayer from Paul. He prays that the God of peace would sanctify us completely... body, soul and spirit. Keep in mind that it is God that does the sanctifying, not us! It is His work to do and as Paul says, He is faithful and He will do it!
If you are struggling in your Christian life today, feeling like you are unable to live a sanctified life in your own strength, my encouragement to you is... you are right! You can't do it! Only the God of peace can sanctify you through and through.
So don't worry. Relax. Take a deep breath and know that He who called you is faithful, and He will do in your life the things that only He can do. My prayer is that we would not trust in our own faith, but in the faithfulness of our Father.
2 Timothy 2:13
If we are faithless, he remains faithful. He can’t deny himself.” (WEB)