To create a MERN stack blog, you'll need to follow these steps:

• Set up a development environment: You'll need to install Node.js, Express, React, and MongoDB to build your website.

• Build the back-end: Create a MongoDB database to store your users' data, such as usernames, passwords, posts, and comments. You'll then need to create a REST API using Express that interacts with your database to handle user authentication and data management.

• Build the front-end: Use React to create the user interface for your website, including the login page, registration page, post and comments page, and profile page.

• Implement authentication: You'll need to implement secure authentication for your users, such as storing hashed passwords in the database and using JSON Web Tokens (JWT) to validate user sessions.

• Create post and comment functionality: You'll need to add functionality to allow users to create posts, and for other users to leave comments on those posts.

• Implement profile functionality: You'll need to create a profile page that displays the user's information, such as their username, posts, and comments.

• Add sections: To organize your website's content, you can add sections to categorize posts and make it easier for users to find what they're looking for.

• Add experts with a tick: To recognize experts in your community, you can add a feature that allows users to mark themselves as experts in certain topics, and display a special symbol next to their name (e.g., a tick).

By following these steps, you'll be able to create a MERN stack blog website.