John Gill Commentary Ezekiel 28:15

"Thou wast perfect in thy ways from the day that thou wast created, till unrighteousness was found in thee." — Ezekiel 28:15 (ASV)

You were perfect in your ways from the day that you were
created
From the time that Tyre became a kingdom, or this king was set over it, everything was wisely conducted, and all things happily succeeded; so when the church of Rome was first formed in the times of the apostles, it was laid on a good foundation; it was set up according to the rule of the word; its bishop or pastor was one of a sound judgment, a good life and conversation, and so continued In succession for a considerable time; these held the true faith and doctrine of Christ, and kept it incorrupt, and lived holy lives:

till iniquity was found in thee ;
pride, blasphemy against God, and contempt of his people, as well as violence and deceit; all this was found in the king of Tyre in later times: so in the church of Rome, when the man of sin was revealed, there were pride, haughtiness, and ambition, found in it; blasphemy against God and Christ, and the saints: false doctrine, false worship, superstition, and idolatry.