When you are creating a new wordpress theme, some time read more tag not working you blog. “Read more” are not showing on the front end of your blog though you are using read more tag in wordpress post.
To solve this problem you need to follow two simple step:
<?php global $more;?> before the loop.
Add this code inside loop.
<?php $more = 0;the_content(__('Read more', 'theemename')); ?>