Three.js rotation

HTML

<script src=http://mrdoob.github.io/three.js/build/three.min.js ></script>
<script src=http://mrdoob.github.io/three.js/examples/js/controls/OrbitControls.js ></script>

JavaScript

var renderer, scene, camera, controls;
	var geometry, material, line, vertices, last, _initTranslation, _initRotation, initScale, rotateMatrix;

	var deg = 0;

	init();
	animate();

	function init() {

		document.body.style.cssText = 'margin: 0; overflow: hidden;' ;

		renderer = new THREE.WebGLRenderer( { alpha: 1, antialias: true, clearColor: 0xffffff }  );
		renderer.setSize( window.innerWidth, window.innerHeight );
		document.body.appendChild( renderer.domElement );
		scene = new THREE.Scene();

		camera = new THREE.PerspectiveCamera( 40, window.innerWidth / window.innerHeight, 1, 1000 );
		camera.position.set( 5, 5, 5 );
		controls = new THREE.OrbitControls( camera, renderer.domElement );
    
    geometry2 = new THREE.BoxGeometry( .5, .5, .5 );
    material2 = new THREE.MeshNormalMaterial();
    cube = new THREE.Mesh( geometry2, material2 );
    scene.add( cube );       
    

		material = new THREE.LineBasicMaterial({ color: 0x0077ff }); 
		geometry = new THREE.Geometry();
		geometry.vertices.push( new THREE.Vector3( 0, 0, 0) );
		line = new THREE.Line( geometry, material ) 
		scene.add( line );
    
    var sphereAxis = new THREE.AxesHelper(20);
    scene.add(sphereAxis);

		addStep();
    
    cube.lookAt(new THREE.Vector3(0.4,0,0.9));

	}

	function addStep() {

		vertices = geometry.vertices;
		last = vertices[ vertices.length - 1 ];
		vertices.push( 

			new THREE.Vector3(0.4,0,0.9) 

		);

		geometry = new THREE.Geometry();
		geometry.vertices = vertices;

		scene.remove( line );
		line = new THREE.Line( geometry, material )
		scene.add( line );

	}

	function animate() {
      
    rotate(deg)
    
    deg += 5
    
	  requestAnimationFrame( animate ); 
	  renderer.render(scene, camera);
	  controls.update();

	}
  
  function rotate(deg) {
    _initTranslation = new THREE.Vector3();
    _initRotation = new THREE.Quaternion();
    _initScale = new THREE.Vector3();
    rotateMatrix = new THREE.Matrix4();
     
   ...