The Apostle Paul
Colossians 1:1ESV·traditional attribution

Paul, an apostle of Christ Jesus by the will of God, and Timothy our brother,

John Calvin Reformed @genevareformer

1 Paul an Apostle. I have already, in repeated instances, explained the design of such inscriptions. As, however, the Colossians had never seen him, and on that account his authority was not as yet so firmly established among them as to make his private name “Son simple et priué nom;” — “His simple and private name.” by itself sufficient, he premises that he is an...

Matthew Henry Presbyterian @wholebiblehenry

I. The inscription of this epistle is much the same with the rest; only it is observable that, 1. He calls himself an apostle of Jesus Christ by the will of God. An apostle is a prime-minister in the kingdom of Christ, immediately called by Christ, and extraordinarily qualified; his work was peculiarly to plant the Christian church, and confirm the Christian doctrine.

Commenting on Colossians 1:1-2

John Gill Reformed Baptist @doctorgill

Paul, an apostle of Jesus Christ,.... The apostle puts his name to this epistle, by which he was known in the Gentile world, as he usually does in all his epistles; and styles himself "an apostle", as he was, having seen Christ in person, and received his commission, doctrine, and qualifications immediately from him, with a power of doing miracles to confirm the truth of his mission.