I need only one template

I've altered the templates to display ALL cases/options (Log in, Register, Reset password). See attached image. I'm theming all my templates the same. So, now it doesn't seem like I need four different templates. I would like to use just one: "page--user--login.tpl.php" for example, but I don't know how to alter the module file to work that way. Is this possible and something you wouldn't mind doing?

Below is the changes I've made. Now, all four templates have identical "bottom_part" 's

<?php

/**
 * @file
 * User login page - Template file.
 */
?>

<div id="auth_box" class="login">
  
  <div id="middle_part">
    <h2 class="title"><?php print $title; ?></h2>

    <?php print $messages; ?>
    
    <?php print render($page['content']); ?>
  </div>

  <div id="bottom_part">
    <div class="login_link b-link">
      <?php print l(t('Login'), 'user/login'); ?>
    </div>
    
    <?php if (variable_get('user_register')): ?>
    <div class="register_link b-link">
      <?php print l(t('Register'), 'user/register'); ?>
    </div>
    <?php endif; ?>
    
    <div class="password_link b-link">
      <?php print l(t('Reset'), 'user/password'); ?>
    </div>
  </div>
    <div class="back_link">
      <a href="<?php print url('<front>'); ?>">&larr; <?php print t('Home'); ?> </a>
    </div>
</div>