jg, are you kidding? Since when “lord” became an exclusively christian reference? It may refer to “god” in any monotheistic religion.

But I digress. What we have in “the year of our Lord one thousand seven hundred and eighty seven” is nothing more than 1787 AD. As I’m sure you learned in your public school, AD stands for anno domine, literally “year of the lord” and is simply a system for dating. You don’t need to be a christian to use the AD or BC nomenclature when referring to dates.