app.get not defined when calling a separate .js file node.js

Here is the app.js file:

   var cluster = require('cluster');
   if(cluster.isMaster){
   var cpuCount = require('os').cpus().length;
   for(var i = 0; i < cpuCount; i++){
   cluster.fork();
   }
   cluster.on('exit',function(){
   console.log('A cluster died\n A cluster was created!');
   cluster.fork();
   });
 }else{
 var bcrypt = require('bcrypt'),
  bodyParser = require('body-parser'),
  express = require('express'),
  session = require('express-session'),
  isemail = require('isemail'),
  nodemailer = require('nodemailer'),
  path = require('path'),
  r = require('rethinkdbdash')({
    port:28015,
    host:'localhost',
    db: 'FPC'
  }),
  socket = require('socket.io');
  var app = express();
app.use(bodyParser.urlencoded({extended:true}));
app.use(bodyParser.json());

var login = require(path.join(__dirname+'/config/login.js'));
}

Here is the config/login.js file

app.get('/login',function(req, res){
   res.sendFile(path.join(__dirname+'/www/CreateAccount/index.html"));
});

When I try to launch the app it gives me an error

ReferenceError: app is not defined
at Object.<anonymous> (C:\Users\yeet\Documents\Projects\website\config\login.js:1:63)
at Module._compile (module.js:571:32)
at Object.Module._extensions..js (module.js:580:10)
at Module.load (module.js:488:32)
at tryModuleLoad (module.js:447:12)
at Function.Module._load (module.js:439:3)
at Module.require (module.js:498:17)
at require (internal/module.js:20:19)
at Object.<anonymous> (C:\Users\yeet\Documents\Projects\website\app.js:29:3)
at Module._compile (module.js:571:32)
at Object.Module._extensions..js (module.js:580:10)
at Module.load (module.js:488:32)
at tryModuleLoad (module.js:447:12)
at Function.Module._load (module.js:439:3)
at Module.runMain (module.js:605:10)
at run (bootstrap_node.js:423:7)

I can't figure out why it won't just take var app = express from the app.js. And requiring all the needed modules to run this removes the purpose of making login.js it's own file

via JavascriptCoding Guru