After editing the theme, "read more" is always shown. How to remove it?

Hello,

I recently edited a theme and I customized it much.

But now, when I open my blog, I see that all of my posts get automaticly a Read More link. I don’t know how to disable it. I know that it has something to do with Functions.php in my theme.

( my theme is on local host and not online, so I cannot give you any URL unfortunately)
Can you please help me? thanks.