How do I display a wordpress page content?

This is more concise:

<?php echo get_post_field('post_content', $post->ID); ?>

and this even more:

<?= get_post_field('post_content', $post->ID) ?>

For people that don't like horrible looking code with php tags blasted everywhere...

<?php
if (have_posts()):
  while (have_posts()) : the_post();
    the_content();
  endwhile;
else:
  echo '<p>Sorry, no posts matched your criteria.</p>';
endif;
?>

@Marc B Thanks for the comment. Helped me discover this:

<?php if ( have_posts() ) : while ( have_posts() ) : the_post();
the_content();
endwhile; else: ?>
<p>Sorry, no posts matched your criteria.</p>
<?php endif; ?>

@Sydney Try putting wp_reset_query() before you call the loop. This will display the content of your page.

<?php
    wp_reset_query(); // necessary to reset query
    while ( have_posts() ) : the_post();
        the_content();
    endwhile; // End of the loop.
?>

EDIT: Try this if you have some other loops that you previously ran. Place wp_reset_query(); where you find it most suitable, but before you call this loop.