Washington used the Farewell Address to validate the power he held during his presidency. He emphasized the importance of a centralized government and stressed the imperative of defending the nation against domestic or foreign threats. Washington also implored the people to identify themselves as Americans, to embrace their national identity.
Washington proved during the war that it was not the number of victories that mattered, but the ground one maintained. Keeping the Continental Army intact despite its losses is what ultimately ran Britain down. His political theories followed the same strategy - in order to survive, the country needed time more than easy victories and successes.
In his final message to Congress, before his official retirement, Washington strongly suggested that the other branches of the federal government expand so that they could compensate for the loss of a powerful executive who performed many of the federal duties on his own.