Christ Jesus seeks from these “fallen” Christians a return to their former manner of thinking, and thus acting. The term used for “repent” describes a change of mind, where you replace your pattern of thinking with another pattern. These Christians of Ephesus cannot shine brightly as long as they do not love the Saviour (and so the brethren) the way they used to. A change of mind will produce a change of conduct, namely, they’ll do again the works they did at first.
5 Remember therefore from where you have fallen; repent, and do the works you did at first. If not, I will come to you and remove your lampstand from its place, unless you repent.