bog on the theme/website down

Hello, There is an error on the theme. How do I get it back up. I just contacted my hosting and they said that it is the theme causing this.

Can you help me please

Fatal error: Class ‘WP_Customize_Section’ not found in /home1/theemps1/public_html/wp-content/themes/creativ-blog/inc/hook/basic.php on line 132

May thanks , my website is down

The page I need help with: [log in to see the link]