Problems with loop

I have this loop in my index.php:

      <?php if (have_posts()) :
          while (have_posts()) :
            get_template_part( 'post' );
          endwhile;
        endif; ?>

which calls this template

<?php   
 ?>
 <h2 id="post-<?php the_ID(); ?>">
 <a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link to <?php the_title(); ?>">
 <?php the_title(); ?></a></h2>
 <?php the_post();
 the_content(); ?>
 <p class="date"><?php the_time('l, j F Y'); ?> </p>
 <?php trackback_rdf();
?>

The loop behaves strangely printing out titles and posts in this order:

• Title post #1

• Content post #1 (and this is ok, but then…)

• Title post #1

• Content post #2

• Title post #2

• Title post #3 (and so on…)

What am I doing wrong?