erase iPhone

This document has a list of things to do if your iPhone, iPad, or iPod touch is lost or stolen. --> If your iPhone, iPad, or iPod touch is lost or stolen - Apple Support

Look at the individual links for what each service does.

If the phone is erased......all of your data (including credit, debit, or prepaid cards for Apple Pay) is deleted from the device. The phone will look like it did when you purchased it.....assuming your phone was new.