People keep telling me I am a new creation, but I feel like the same person with the same problems. What am I missing?

“A new heart also will I give you, and a new spirit will I put within you: and I will take away the stony heart out of your flesh, and I will give you an heart of flesh.”

Ezekiel prophesied to exiles who understood by then that their real problem was not Babylon but themselves, generations of failure they could not reverse by trying harder. God's answer is a transplant rather than a repair: a new heart given, not gradually developed. It is a promise about what God undertakes to do in a people, which is worth knowing when your own effort appears to be producing nothing.

“Being confident of this very thing, that he which hath begun a good work in you will perform it until the day of Jesus Christ:”

Paul wrote this from custody to a church he loved, early in a letter full of open affection. The verb he chooses points to a project already begun and guaranteed to be completed by the one who started it, not by the Philippians keeping pace. Growth in his framing is unfinished by definition. Feeling like the same person is entirely normal in the middle of a work still underway.