There Are five Entities and they are "Jiva,Eshwara,Maya,Brahman,ParaBrahman".
Out of these five ParaBrahman is the Ultimate.Whan there was a need on the earth Parabrahman through his Shakti made an avtar of Krishna.So the fact that Krishna had 16000+ wives is true and they were not bodily related to him but related as devotees.They were such staunch devotees to him that when they asked him to show his abode Krishna did not show Golok But showed them the abode of Parabrahman.having so many wives is also a manushya Charitra done by lord. Krishna is not the ParaBrahman but is the form given by ParaBrahman Through his Shakti to kill Kans.Only Radha's idol is placed beside Krishna Out 16000 wives because she was the best devotee of Krishna.If we become a devotee like Radha then only we can achieve Krishna.