Ajax search form giving Object of class Symfony\Component

Quiz app, Trying to make a search form with ajax, but getting this when I click submit, using mac,laravel 5.2.29

    ErrorException in QuizController.php line 32: Object of class Symfony\Component\HttpFoundation\ParameterBag could not be converted to string

This is my form

    <form class="navbar-form navbar-left" id="formSearch" method="post" action="{{route('quiz.searchMain')}}">
                {{ csrf_field() }}
               <div class="form-group">
                 <input type="text" id="query" class="form-control" placeholder="Search">
               </div>
               <button id="searchSubmit" type="submit" class="btn btn-default">Submit</button>
            </form>

and my ajax jquery code

    $("#searchSubmit").click(function(){
            $.ajax({
                type:'POST',
                url:'quiz/searchMain',
                data:{
                    '_token':$('input[name=_token]').val(),
                    'query':$('#query').val()
                },
                success:function(data){
                    console.log("we succeded" + data);
                }
            });
        });

right now testing to see if it returns data properly with console.log, but aiming to make it autocomplete eventually

controller that gives the response data QuizController.php

        public function searchMain(Request $request){

        $query = $request->query;
        $results = Quiz::where('title','like',"$query%")->get();
        if (Request::wantsJson()) return $results;
    }

I guess there is a problem with $results since its on line 32, how would I fix this and any tips to improve the implementation ajax search for this would be good.