Ruby layout not loading while calling render

Question

I am using model validation I want to load the default layout with register.html.erb page. But while i am using rendering only register my layout not loading. Please check -

#users_controller.rb
def create
    @user = User.new(create_user_params)
    #raise @user.inspect
    respond_to do |format|
      if @user.save
        format.html { redirect_to :success, notice: 'Registration was successfully created.' }
        format.json { render :success, status: :created, location: @users }
      else
        format.html { render :register }
        format.json { render json: @users.errors, status: :unprocessable_entity }
      end
    end
  end

Here is format.html { render :register } I have successfully getting my validating error message. But design missing only loading register.html.erb. Complete page not coming with layout.If I am using redirect_to :register instead of render :register my page redirect successfully to register page but my error message not showing.

How I will showing both my validating error and design?

users_controller.rb

class UsersController < ApplicationController
  before_action :set_user, only: [:show, :edit, :destroy, :register_success]


  # GET /users
  # GET /users.json  
  def index
    @users = User.all
  end

  # GET /users/1
  # GET /users/1.json
  def show
  end

  # GET /users/new
  def new
    @user = User.new
  end

  # GET /users/1/edit
  def edit
  end

  #=============================CHINU CODE START
  def login
    @title = 'Login'
    render layout: 'login'
  end
  def create_login
    user = User.authenticate(params[:user][:username], params[:user][:password])
    if user
      log_in @user
      redirect_to @user
    else
      flash[:danger] = 'Invalid email/password combination' # Not quite right!
      redirect_to :back
    end
  end
  def register
    @user = User.new
    @title = 'Register'
    render layout: 'login'
  end

  def create
    @user = User.new(create_user_params)
    #raise @user.inspect
    respond_to do |format|
      if @user.save
        format.html { redirect_to @users, notice: 'Registration was successfully created.' }
        format.json { redirect_to :success, status: :created, location: @users }
      else
        format.html { render :register }
        format.json { render json: @users.errors, status: :unprocessable_entity }
      end
    end
  end

  def register_success
    raise @user.inspect
  end

  def check_email    
    email = params[:user]
    user = User.where("email = ?", email).first
    if user.present?
      render :json =>  [false , "This email is already taken"]
    else
      render :json =>  [true , "Email available"]
    end
  end
  def check_username   
    username = params[:user]
    user = User.where("username = ?", username).first
    if user.present?
      render :json =>  [false , "Username has already been taken"]
    else
      render :json =>  [true , "Username available"]
    end
  end
  #=============================CHINU CODE END

  private
  # Use callbacks to share common setup or constraints between actions.
  def set_user
    @user = User.find(params[:id])
  end

  # Never trust parameters from the scary internet, only allow the white list through.
  def user_params
    params.require(:user).permit(:name, :username, :email, :password, :image, :dob, :photo, :address)
  end
  def create_user_params
    params.require(:user).permit(:name, :username, :email, :password, :dob, :address)
  end

  def login_user_params
    params.require(:user).permit(:username, :password, :password_confirmation)
  end
end

application_controller.rb

class ApplicationController < ActionController::Base
  # Prevent CSRF attacks by raising an exception.
  # For APIs, you may want to use :null_session instead.
  protect_from_forgery with: :exception
  include SessionsHelper

end