The LORD prepared a vineyard, protected it, took care of it, used the best choice of vine, and prepared a winepress expecting to reap bountifully.  What came out is not what He wanted:  "...when I looked that it should bring forth grapes, brought it forth wild grapes?"  Therefore, His judgement was equal to what He gave: took away His protection, He would no longer care for its well being, and no longer allow it to be supplied. 

Of course He is immediatly talking about Israel but the parable has a universal truth:  He expects something out of His work.  Judge now between you (the vineyard) and Him.  He expects something out of His labor in you.  He labored in death to GET something out of you.  What are you bearing?  Wild grapes of your own volition?  Or grapes of righteousness from His will?  Bear the right fruit and the Lord of the vineyard will prune you and cause you to flourish.