I’m assuming you added $this->middleware('auth'); inside the constructor of your controller to get the authentication working. In your login/register forms, if you are using {!! Form::someElement !!}, add the following line at the top as well:
{!! csrf_field() !!}
Or if you are using input tags inside your forms, just add the following line after <form> tag:
<input type="hidden" name="_token" value="{{ csrf_token() }}">
Hope this helps.