excerpts on index

Open the post.php and change the_content into the_excerpt.

excellent! thanks for the help

That didn’t work, it shows it only as a excerpt everywhere and not the full article.

By “everywhere” you mean archives, categories and even single post view? That means you don’t have any other templates in your theme. And according to Template Hierarchy WP will use index.php when a template is not in the theme.
You have two choices:
a) create those templates with the_content tag
b) use if statements in your index.php to display either content or excerpt depending on what is viewed.

the index calls for post.php to pull up the posts. I created another template called post2.php and had it pull the excepts instead of content and then the full article is shown when you click on it

thanks for the help, it worked