Undefined method in User_Controller - To do List

I'm working on a to-do list in rails and I'm getting the following: undefined method `items' for nil:NilClass in my users_controller.rb.

The program was working to the point where I could delete and create the list and have it take me to the new_list_path. However, after I came back a day later, I got the undefined method.

Currently, the user is logged in and there is no list. I tried to add a list via rails console but that didn't work.

users_controller.rb

class UsersController < ApplicationController

 def show
  return redirect_to new_list_path unless current_user 
  @list = current_user.list
  @items = @list.items 
 end
end

I am directing everything to go the View/Users/Show page with some partials:

users/show.html.erb

 <h1><%= @list.title  %></h1>
 <%= link_to "Delete List", @list, method: :delete %>
 <h2 class="media-heading"><%= current_user.name %></h2>
 <%= render partial: 'items/form'%>
 <%= render partial: 'items/item', collection: @items %>

Partials are here

items/_form.html.erb

 <%= form_for [@list, @list.items.new] do |f| %> 
  <div class="form-group">
    <h4>Add an Item:</h4><br/>
  </div>
  <div class="field">
    <%= f.label :name %>
    <%= f.text_field :name, class: 'form-control', placeholder: "Add an Item:" %>
  </div>
  <div class= "form-group">
    <%= f.submit "Create Item", class: 'btn btn-success' %>
  </div>
 <% end %>

items/_item.html.erb

<small class="media-heading">
  <p><%= item.name %></p>
   <%# time_ago_in_words(item.created_at) %> 
</small>

Here are my other two controllers:

lists_controller.rb

class ListsController < ApplicationController
  before_action :authenticate_user!

  def new
    @list = List.new
  end

  def create
     @list = List.new(list_params)
     @list.user = current_user

    if @list.save
      flash[:notice] = "List was saved."
      redirect_to current_user
    else
      flash[:error] = "There was a problem saving your list."
      redirect_to user_path(current_user)
    end
  end

  def destroy
    @list = List.find(params[:id])
    if @list.destroy
      redirect_to new_list_path
     else
      redirect_to current_user
    end
  end

  def edit
  end

   private
   def list_params
     params.require(:list).permit(:title)
   end
 end

items_controller.rb

class ItemsController < ApplicationController

  def show
    @items = Item.all
  end

  def create
    @list = List.find(params[:list_id])
    @item = Item.new(item_params)
    @item.list = @list # after initializiation, before saving 
    if @item.save
      flash[:notice] = "Item was saved."
      redirect_to current_user
    else
      flash[:error] = "There was a problem saving your item."
      redirect_to current_user
    end
  end

  private
  def item_params
    params.require(:item).permit(:name)
  end
 end

I'm wondering how it's broken when it worked previously.