My contractor said that the work was finished and I paid him, why do I need a final inspection?

Final inspections should be completed before the final payment.  A contractor who hasn't received final payment is more likely to come back and correct a failed inspection versus a paid one.  The New Jersey Division of Consumer Affairs Rule:  N.J.A.C. 13:45A-16.2(a)10.ii states:  "FOR INSPECTION ON CONSTRUCTION PERMITS FOR:  BUILDING, ELECTRIC, PLUMBING, FIRE PROTECTION OR ELEVATOR, FINAL PAYMENT TO THE CONTRACTOR IS NOT REQUIRED TO BE MADE BEFORE A FINAL INSPECTION IS PERFORMED."