NT points out the two most famous verses in this segment are verse 15 and 20. One references the lukewarm Christians in the church of Laodicea and the other references the Lord knocking at the door of our heart. Both are worthy of commenting on, but both have been commented upon by others far smarter than me for centuries.
Instead, I prefer to address the spirit of the letters; specifically the closing words common to all of them. As I reflect, I see all the love and all the warnings that have been given to all the churches and all the church people for three Chapters. And as stated best by the author John, inspired by our Lord, and paraphrased by NT, “Let the one who has an ear, listen to what the spirit is saying to the churches.” I think that says it all. Amen.