The love God is said to bear us is "unconditional". People hear that and think "o yea that sounds good im gonna repeat that" and here we are. Plus theres something about how man's imperfection bars us from having love without conditionals. some people also posit that the love a (well-trained) dog has for its master is also unconditional but i would say that it is in fact dependant upon master feeding and not abusing dog