I am convinced and confident of this very thing, that He who has begun a good work in you will [continue to] perfect and complete it until the day of Christ Jesus [the time of His return].

because he came close to death for the work of Christ, risking his life to complete what was lacking in your service to me [which distance prevented you from rendering personally].

I rejoiced greatly in the Lord, that now at last you have renewed your concern for me; indeed, you were concerned about me before, but you had no opportunity to show it.