1 John 2:21 - Coke's Commentary on the Holy Bible

I have not written unto you— Though St. John uses the word εγραψα, I have written, as he had done before, 1 John 2:14 yet he speaks of what he was now writing; for there is no reason to think that he had written his Gospel or one Epistle to these Christians before this. See 1 Peter 5:12. And his using the aorist is well accounted for by Beza, who observes, that he refers to the time when the epistle would be read; which manner of speaking is used by the Latins, as well as the Greeks.