Albert Barnes Commentary Colossians 4:13

"For I bear him witness, that he hath much labor for you, and for them in Laodicea, and for them in Hierapolis." — Colossians 4:13 (ASV)

For I bear him record. Paul had had abundant opportunity to know what his feelings were regarding these churches.

A great zeal for you: a great desire to promote your welfare.

And them that are in Laodicea. Laodicea was the capital of Phrygia, and not far from Colosse. There was a church there. (See the Introduction and the notes on Colossians 4:16).

And them in Hierapolis. This was also a city in Phrygia, not far from Laodicea and Colosse. It was situated under a hill to the north and had on its south a large plain about five miles across.

Opposite Hierapolis, on the south side of that plain, was Laodicea, with the river Lycus running between them, closer to Laodicea than to Hierapolis. This place is now called by the Turks Pambuck-Kulasi, or the Cotton-Tower, because of the white cliffs around it.

It is now utterly forsaken and desolate, but its ruins are so magnificent that they show it was once one of the most splendid cities in the East. It was celebrated for the hot springs in its vicinity and, because of the numerous temples erected there, it received the name Hierapolis, or the holy city. The principal deity worshipped there was Apollo. (See Travels by T. Smith, B.D. 1678; compare to the notes on Colossians 4:16).

From the allusion to it here, it would seem that there were Christians there in the time of Paul, though there is no mention of a church there. It is nowhere else mentioned in the New Testament.