There is no apostle named John Paul. There is an apostle named John and another apostle named Paul.

He called himself the Apostle to the Gentiles.

There is no apostle named John Paul. There is an apostle named John and another apostle named Paul.

This is the Apostle Paul who wrote down this Epistle.

He calls himself an apostle of Jesus Christ.

Eph 1:1 From Paul, who by God's will is an apostle of Christ Jesus--- To God's people in Ephesus, who are faithful in their life in union with Christ Jesus: