The name Philadelphia means brotherly love. The city was given its name from the brotherly love displayed by Attalus II towards his brother Eugene which won him the moniker of Philadelphus. Philadelphia is known to have been a missionary city though the term is probably not the same as what we would think of as a missionary endeavor today.
The city was founded as a launch point for the spread of Greek culture and language into the regions of Lydia and Phrygia. In that sense from its conception, it was a missionary city focussed on promoting the unity of spirit, customs, and loyalty within the empire. In this sense, the city was a devoted Grecian missionary and was successful in its endeavors.
In the early part of the new millennium, the Lydian tongue had become obsolete and Greek had become the only spoken language in the country. The city itself was located at the gateway of the fertile Valley of Hermus and was sometimes referred to as Little Athens.