“For I am sure of this very thing, that the one who began a good work in you will perfect it until the day of Christ Jesus.”
Here we have a verse the we love to personalize to help us keep up hope for when we feel inadequate as an individual. This verse was however, written to the church at Philippi. If you keep the verse in its context, and add a little southern translation, the phrase “in you” would be rendered “in y’all”. Look back in verse 1, it says “To all God’s holy people:“. At no point between verse 1 and verse six is there a change of address to a single person or position in the church. The address is to the entire group of Christians. There was the automatic assumption that the Christians would all be gathering regularly to study the scriptures and it is most likely they would have read this entire letter (we call it a book) during this gathering. So what the Philippians heard was that as a body of believers, God would be continuing to make them better Christians until the day that Jesus returned to take them to heaven.