Display Comments in Front page #wptips http://www.deluxeblogtips.com/2013/01/display-comments-in-homepage.html

front-page.php

<?php
while ( have_posts() ) : the_post();
    if ( have_comments() )
        {
            echo '<ol class="comment-list">';
            wp_list_comments();
            echo '</ol>';
        }
endwhile;
?>

functions.php

<?php
$comments = get_comments( array(
    'post_id' => get_the_ID(),
    'status' => 'approve',
) );
if ( !empty( $comments ) )
{
    echo '<ol class="comment-list">';
    wp_list_comments( array(
        'callback' => 'si_comment_layout',
        'type'     => 'comment',
    ), $comments );
    echo '</ol>';
}
function si_comment_layout( $comment, $args, $depth )
{
    ?>
    <li>
        <div class="comment-author">
            <?php echo get_avatar( $comment, 30 ); ?>
        </div>
        <div class="comment-content">
            <?php printf( '<cite class="url fn n">%s</cite>', get_comment_author_link() ); ?>:
            <?php echo strip_tags( get_comment_text() ); ?>
        </div>
    <?php
}
?>