Custom text on Blog page

Hey there,
I tried to look it up here but without any success, so I hope this is not gonna be a duplicate question or anything, but I’m having this trouble:

I have some default Post page called “Blog”, as seen on screenshot below:
http://mathy.cz/dotaz/01-posts_page.png
http://mathy.cz/dotaz/02-page-blog.png

And I would like to show the text from the page at the very beggining of the blog page as well as I have it on my other page, which I’m bulding now on roots.io :
http://logicworks.mathy.cz/?page_id=126#vypis_clanku (this web is also still unfinished)
So first up, I would like to have a content text from the page and then list of the blog posts. But all I see there, is just the list of the post, but not the text from the page:
http://mathy.cz/dotaz/03-frontend.png

Normaly, I would add <? the_content(); ?> to the template of the blog, but this would be overwriten after some future update of the Enfold.

So my question is – it there any way how to add a text from the page to the list of the blog post, or will I have to add it to the code of the template?
I heard something about child themes, but didn’t have time to study it properly yet.

Thanks in advance for your reply and thanks for the awesome Enfold theme!
Best regards
Martin