<?php
$args = array(
        'posts_per_page' => 1,
        'tag' => 'featured',
    );

    $featured = new WP_Query($args);

    if($featured->have_posts()): while($featured->have_posts()): $featured->the_post();
        the_title();
        the_content();
    endwhile; else:

    endif;
?>