Adding div around "the_content"

I am trying to put a transparent background around the text of a post, but I want to leave the post Title outside the background, so in the theme directory (picture-perfect theme), in page.php I did:

<br />
<?php while (have_posts()) : the_post(); ?><br />
  <div class="post" id="post-<?php the_ID(); ?>"><br />
    <h2 id="the_title"><?php the_title(); ?></h2></p>
<p>     <div id="post_text"><br />
	<?php the_content();?><br />
      </div></p>
<p>  </div><br />
<?php endwhile; ?><br />

When I test, it’s as if I had never written the “<div id=”post_text”>” or its closing tag.

How can I insert a div around the_content() ?

Thank you