// Remplacer ça :

<ul class="col-md-10 col-md-offset-1 col-xs-10 col-xs-offset-1 all-employed" >
    <h1><?php echo $title_team ?></h1>
    <?php wp_reset_postdata(); ?>
            <?php wp_reset_postdata();
        $args = array(
            'post_type' => 'about',
            'category__and' => array($cat_ID,61),
            'posts_per_page' => 4,
            'order' => ASC,
        );
        query_posts( $args );?>
        <?php if (have_posts()) : ?>
        <?php while (have_posts()) : the_post(); ?>
            <?php
                $urlImage = get_post_thumbnail_id();
                $urlImage = wp_get_attachment_image_src($urlImage,'large');
                $urlImage = $urlImage[0];
            ?>
                <li class="col-md-3 col-xs-12">
                    <div class="thumbnail-article" style="background-image:url('<?php echo $urlImage; ?>')"></div>
                    <h2 class="title" id="title-<?php the_ID() ?>"><?php the_title(); ?></h2>
                    <div class="content" id="content-<?php the_ID() ?>"><?php the_content(); ?></div>
                </li>
        <?php endwhile; ?>
        <?php endif; ?>
    </ul>
    <div class="col-md-10 col-md-offset-1 col-xs-10 col-xs-offset-1" style="margin-bottom:100px" >
        <?php wp_reset_postdata(); ?>
            <?php wp_reset_postdata();
        $args = array(
            'post_type' => 'about',
            'category__and' => array($cat_ID,61),
            'posts_per_page' => 1,
            'order' => ASC,
            'offset' => 4,
        );
        query_posts( $args );?>
        <?php if (have_posts()) : ?>
        <?php while (have_posts()) : the_post(); ?>
            <?php
                $urlImage = get_post_thumbnail_id();
                $urlImage = wp_get_attachment_image_src($urlImage,'large');
                $urlImage = $urlImage[0];
            ?>
        <?php endwhile; ?>
        <?php endif; ?>
    </div>
    <ul class="col-md-10 col-md-offset-1 col-xs-10 col-xs-offset-1 all-employed" >
    <?php wp_reset_postdata(); ?>
            <?php wp_reset_postdata();
        $args = array(
            'post_type' => 'about',
            'category__and' => array($cat_ID,61),
            'posts_per_page' => 4,
            'order' => DESC,
        );
        query_posts( $args );?>
        <?php if (have_posts()) : ?>
        <?php while (have_posts()) : the_post(); ?>
            <?php
                $urlImage = get_post_thumbnail_id();
                $urlImage = wp_get_attachment_image_src($urlImage,'large');
                $urlImage = $urlImage[0];
            ?>
                <li class="col-md-3 col-xs-12">
                    <div class="thumbnail-article" style="background-image:url('<?php echo $urlImage; ?>')"></div>
                    <h2 class="title" id="title-<?php the_ID() ?>"><?php the_title(); ?></h2>
                    <div class="content" id="content-<?php the_ID() ?>"><?php the_content(); ?></div>
                </li>
        <?php endwhile; ?>
        <?php endif; ?>
    </ul>

// Par ça :

    <ul class="col-md-10 col-md-offset-1 col-xs-10 col-xs-offset-1 all-employed" >
    <h1><?php echo $title_team ?></h1>
    <?php wp_reset_postdata(); ?>
            <?php wp_reset_postdata();
        $args = array(
            'post_type' => 'about',
            'category__and' => array($cat_ID,61),
            'posts_per_page' => 20,
            'order' => ASC,
        );
        query_posts( $args );?>
        <?php $count = 0;  ?>
        <?php if (have_posts()) : ?>
        <?php while (have_posts()) : the_post(); ?>

            <?php
                $count += 1
                if ($count == 4 ) : {
                    $count = 0; ?>
                </ul>
                <ul class="col-md-10 col-md-offset-1 col-xs-10 col-xs-offset-1 all-employed" >
                <?php } ?>

            <?php
                $urlImage = get_post_thumbnail_id();
                $urlImage = wp_get_attachment_image_src($urlImage,'large');
                $urlImage = $urlImage[0];
            ?>
                <li class="col-md-3 col-xs-12">
                    <div class="thumbnail-article" style="background-image:url('<?php echo $urlImage; ?>')"></div>
                    <h2 class="title" id="title-<?php the_ID() ?>"><?php the_title(); ?></h2>
                    <div class="content" id="content-<?php the_ID() ?>"><?php the_content(); ?></div>
                </li>
        <?php endwhile; ?>
        <?php endif; ?>
    </ul>