Not necessarily. If Germany beat both Serbia and Ghana, and we beat Ghana and draw with Serbia we have the following group table.
GER 3-0-0 9
AUS 1-1-1 4
SRB 0-2-1 2
GHN 0-1-2 1
Even if Serbia draw with Germany we still go through.
All is not lost... yet.
If Germany lose a game, we're in trouble.
Except, Ghana already have three points.