I've got a quote to share and comment on...
The difference between the City of God and the City of Man is like the difference between Christ and Dracula. Christ shed his blood so that you can have eternal life; Dracula sheds your blood so that he can have eternal life (E. Michael Jones).
This really does contrast life in the secular world as opposed to life in God's kingdom...
The world system (the City of Man) is all about sucking life from people in order to sustain itself and grow. It offers no life.
But Jesus sacrifices Himself so we would have life in His kingdom (the City of God)... and in Him be a life-giving force among others.
"Whoever has the Son has life" (1 Jn.5:12).