Just to be on the safe side - refer to increases in "real gdp growth" in ur essays etc...that way inflation is already excluded.
Growth can lead to increases in productivity - there is more capital to invest, better workign conditions can be provided, improve the environment etc ---> growth can then self-perpetuate, and poorer nations can sometimes be stuck in a downward spiral.
Also, growth allows greater specialisation and greater wealth from the advantages of trade/comparative advantage. (poorer countries can't afford to establish complex infrastructure, capital markets etc, and ppl are too focussed on subsistence living for the development of secondary occupations - e.g lawyers, stockbrokers etc....) While specialisation also leads to wealth. Specialisation leads to increases in productivity.
Hmmm reminded of that joke "there's no such thing as a one handed economist - everything is always 'on the other hand' "