You can load content from other pages via the get_pages function:
<?php
$args = array(
'sort_column' => 'menu_order',
'include' => array( 5, 6, 7 ) // your page IDs
);
$my_pages = get_pages( $args );
foreach( $my_pages as $page ){
setup_postdata( $page );
the_title();
the_post_thumbnail();
the_excerpt();
the_permalink();
}
wp_reset_postdata();
?>