Drupal 7 Custom Page shown only for logged-in users
You are creating a custom page, so you should use user_is_anonymous() in the calback of the page.

For example: 

$form['custom_path'] = array(
  'page callback' => 'some_random_function',
);
function some_random_function() {
 if(user_is_anonymous()) { 
  //call the login block
 }
 else {
  // What ever u want.
 }
}