Question

<?php   
 if ( is_home() ) {

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


  <div id="post">

      <?php the_content(); ?>

    </div>


    <?php endwhile;?>


    <?php endif; ?>
} else if (is_page() ) {

 $category = get_post_meta($posts[0]->ID, 'category', true);
}
if ($category) {
$cat = get_cat_ID($category);
$paged = (get_query_var('paged')) ? get_query_var('paged') : 1;
$post_per_page = 4; // -1 shows all posts
$do_not_show_stickies = 1; // 0 to show stickies
$args=array(
'category__in' => array($cat),
'orderby' => 'date',
'order' => 'DESC',
'paged' => $paged,
'posts_per_page' => $post_per_page,
'caller_get_posts' => $do_not_show_stickies
  );
  $temp = $wp_query;  // assign orginal query to temp variable for later use   
  $wp_query = null;
  $wp_query = new WP_Query($args); 
   if( have_posts() ) : 
    while ($wp_query->have_posts()) : $wp_query->the_post(); ?>

  <div id="post">

      <?php the_content(); ?>
    </div>


<?php endwhile; ?>
<?php endif; 

$wp_query = $temp;  

 }  
?>

Answer 1

On line #4 you are opening a new PHP block even though the old one hasn’t been closed yet.

You’ll want to delete the preceding <?php on that line. You don’t need it.

Additionally:

You have an extra endwhile; in your else block. The while loop is started and closed within the if ( is_home() ) { block.

The code starting with } else if (is_page() ) { is not in a PHP block. You should either open a <?php block or not close the preceding one.