Public Relations at its best is sharing with people -- all people -- the gift of truth, and nothing but the truth, so that they all can be the best that they can be and live the best and most wonderful life on earth that they can live.
Public Relations is telling the whole world how loving God is, and how wonderful God's creation is, and how everyone everywhere must reciprocate God's love and turn to him in obedience and humility and surrender.
And doing it all using the best and nicest possible means and methods. And the cleanest and purest possible motives and intentions.
That is what Public Relations is at its best.
In that sense, God sent some of the best people on earth to do Public Relations for him. And he called them his Anbiyaa' and Rusul -- prophets and messengers -- Alaihim Assalam.
After the Prophets and Messengers stopped coming, it is now the role and duty of Muslims in every place and generation to do Public Relations for Allah, which, again, means going and telling everyone everywhere how loving Allah is, and how wonderful his creation is, and how it is now time for them to turn to him.
In every age and place, that is what it means to be a Muslim: Allah's Public Relations Professionals on Earth.