"We are members of one body, we are responsible for each other."
Priestley creates a biblical allusion as used in baptism that we are "members of his body" in Christ. Through this Priestley reinstates the foundational teachings of christianity and morality and therfore socialism too. Alike to jesus providing salvation for mankind it can be thought to as the inspector providing salvation for the birling family and therefpre it can be seen as socialism is the only chance of salvation socity has.
The singular image of "one" serves as a constant reminder of the belief that socialism connects evryone together. Also how there are organs and cells which make up the whole body asnd if these did not all work together we would simply perish just as society is with the capitalist ideology manipulating and corrupting minds.