Page content can be displayed easily and perfectly this way:
<?php if(have_posts()) : ?>
<?php while(have_posts()) : the_post(); ?>
<h2><?php the_title(); ?></h2>
<?php the_content(); ?>
<?php comments_template( '', true ); ?>
<?php endwhile; ?>
<?php else : ?>
<h3><?php _e('404 Error: Not Found'); ?></h3>
<?php endif; ?>
Note:
In terms of displaying content - i) comments_template() function is an optional use if you need to enable commenting with different functionality.
ii) _e() function is also optional but more meaningful & effective than just showing text through <p>. while preferred stylized 404.php can be created to be redirected.