Why high current in forward bias of PN Junction?

Hi all,
Recently I have read something, as we know current always flow through a 
closed path, then how does a current flows through a pn junction 
diode?because electrons from n when moves to p, then as in moves deeper 
in p region many electrons recombine , so the electrons coming back to 
the +ve terminal of the battery to form a closed loop is very low ... 
then why get high current in forward bias?