UserController.rb

class User < ActiveRecord::Base
  def needs_proof?
    self.util_one.blank? && self.letter_approved
  end
  
  # ... etc
end


class UsersController < ApplicationController
  def show
    @user = User.find(params[:id])
      render "userinfo" and return  f current_user.admin?
      render "letter" and return if current_user.letter.blank?
      render "proof" and return if current_user.needs_proof?

      # ... etc
  end
end