Multi theme on one WP installation

I have a site that is currently nothing but Blog Posts. I created this to build up the organic SEO via Content marketing.
Now my main goal of the site is to sell software (currently in development) and I want to use the Enfold theme for the main site which will have only Pages and I want to use the Sahifa theme for my blog side on the SAME URL.

Do you know of a plugin that can let me achieve this?

Hope your following my end goal..

thank you