When you use the more tag in WordPress the post on the index page is "cutting-off" by this tag, leaving on top only what we write above this tag. At the post will be added a Read More link… We can also include the post title in this link and type custom messages also.
Open index.php file (99% of cases)
<?php the_content('Read more...'); ?>
<?php the_content("Continue reading " . the_title('', '', false)); ?>
Please note that we can change the phraze "Continue reading" with our custom message. That’s all, save your file and refresh your blog.
Note: This work if you chose Full text in reading options and use More Tag in post page.