Awful loop usage in WordPress theme index.php

index.php

<?php global $wp_query;
                    query_posts(
                       array_merge(
                           $wp_query->query,
                           array(
                               'orderby' => 'post_date',
                               'order' => 'desc'
                           )
                       )
                    );
               ?>

<?php if (have_posts()) : while (have_posts()) : the_post();?>



<div class="blogEntry">
	<div class="blogDate">
		<span class="blogMonth"><?php the_time('F'); ?></span>
		<span class="blogDay"><?php the_time('j'); ?></span>
	</div>
	<a href="<?php the_permalink(); ?>"><h1 class="balance-text"><?php the_title(); ?></h1></a>
	<?php the_content(); ?>
</div>

<?php endwhile; endif; ?>