On your custom page template, the default loop is working and that's why the loop is fetching content from the page. You need a custom query in this case. Here's the code.

    <?php
    $query = new WP_Query( array(
        'post_type' => 'post',
        'post_status' => 'publish',
    ) );
    if ( $query->have_posts() ) :
        while ( $query->have_posts() ) : $query->the_post();
            get_template_part( 'content', 'home' ); 
        endwhile;
    endif;
    ?>