Sentence:  What that spirit and attitude were we can best understand if we see more precisely how it contrasts with the communist tradition with the <WSD>longest</WSD> continuous history , the one which reached Christianity by the way of Stoicism through the Church Fathers of Late Antiquity . 
Meaning of the word marked with <WSD> tags:  primarily temporal sense; being or indicating a relatively great or greater than average duration or passage of time or a duration as specified