Your question doesn’t actually make sense to me; but I think what you’re saying is “the landing page for my blog only shows post excerpts, to show the full post I need to view a post as a single page; how do I show the full content of my posts on the landing page?”
If that is indeed the case, you’ll need to either create a child theme based on the theme (preferable) or edit the theme’s templates (less preferable but quicker if you’re not happy with the concept of creating child themes).
Regardless of your approach, you’ll need to modify the contents of post-entry.php, which is loaded by the call to get_template_part ('post', 'entry') in index.php. The theme’s post-entry.php file as shipped looks like this …
<?php while (have_posts()) : the_post(); ?>
<div class="post">
<div class="postcontent">
<?php if ( has_post_thumbnail() ) { ?>
<div class="thumbnail-wrap">
<a href="https://wordpress.stackexchange.com/questions/68131/<?php the_permalink(); ?>" title="<?php the_title(); ?>"><?php the_post_thumbnail('post-image'); ?></a>
</div><!-- END thumbnail-wrap -->
<?php } ?>
<h2 class="entry-title"><a href="https://wordpress.stackexchange.com/questions/68131/<?php the_permalink(); ?>" title="<?php the_title(); ?>"> <?php the_title(); ?></a></h2>
<?php the_excerpt(); ?>
</div><!-- END Post Content -->
</div><!-- END Post -->
<?php endwhile; ?>`
… modify this file to change the call to the_excerpt() to the_content() and it should look like this …
<?php while (have_posts()) : the_post(); ?>
<div class="post">
<div class="postcontent">
<?php if ( has_post_thumbnail() ) { ?>
<div class="thumbnail-wrap">
<a href="https://wordpress.stackexchange.com/questions/68131/<?php the_permalink(); ?>" title="<?php the_title(); ?>"><?php the_post_thumbnail('post-image'); ?></a>
</div><!-- END thumbnail-wrap -->
<?php } ?>
<h2 class="entry-title"><a href="https://wordpress.stackexchange.com/questions/68131/<?php the_permalink(); ?>" title="<?php the_title(); ?>"><?php the_title(); ?></a></h2>
<?php the_content(); ?>
</div><!-- END Post Content -->
</div><!-- END Post -->
If I’ve misread your question and this isn’t what you meant, please edit your question to clarify.