If you're not using one of those magazine style template, you might not like the way your blog posts show full length on your homepage. It might give your blog some kind of awkward look especiall if you are having very long posts. It makes your blog pages and search results extra long.
You can however add auto post summary to create a "Read More" link beneath your blog posts, just like the one I use here. Let's get started

First download and back up your template in case something goes wrong.