the_content and the_excerpts PLEASE HELP!!

Hello all, I know this have been asked many many times before and people provided answers, but I just can not seem to get it with my theme

My theme shows full posts on the main page and I want it to show only the summary, I tried searching for the_content tag in my theme’s index.php file but it is not even there!!! i dont have a home.php or category.php i tried searching my whole wordpress installation for the_content and the only places i could find it is in page.php and even when changing it there it doesnt really work.

The other places i found it in my theme formats (image.php, audio.php…) but changing it there makes the post shows the summary even when you click on it and go inside the post!!

Someone please help me, I dont want to use the “more” tag on every post!