John the Apostle
Revelation 2:4ESV·traditional attribution

But I have this against you, that you have abandoned the love you had at first.

Matthew Henry Presbyterian @wholebiblehenry

We have here, I. The inscription, where observe, 1. To whom the first of these epistles is directed: To the church of Ephesus, a famous church planted by the apostle Paul (Acts 19), and afterwards watered and governed by John, who had his residence very much there.

Commenting on Revelation 2:1-7

John Gill Reformed Baptist @doctorgill

Nevertheless I have somewhat against thee,.... So the Jews represent God saying, concerning their fathers, "Abraham", &c. "I have something against them" (a). Christ has nothing against his people, his faithful ministers, and true churches, in a judicial way, or to their condemnation, for there is none to them that are in him; but he has often many things to complain of in them, and...

Albert Barnes Presbyterian @notesbybarnes

Verse 4. Nevertheless I have somewhat against thee. Notwithstanding this general commendation, there are things which I cannot approve. Because thou hast left thy first love. Thou hast remitted-- αφηκας--or let down thy early love; that is, it is less glowing and ardent than it was at first.