Do you want to add multiple authors or editors to your blog? WordPress comes with a built-in user management system that allows you to add users with different roles and capabilities allowing you to add new users without worrying about the safety of your site.

To give someone editorial access to your website, choose “Users” in the sidebar in the Dashboard view of your site:
WordPress dashboard Users tab on the left side, circled

Then, click the “Add Existing” button at the top of the page:
Users page with a list of current users and their information, next to the title Users adding existing button, circled

Finally, enter the email address of the user(s) you’d like to add. And be sure to designate the role you’d like them to have. The different role options determine the level of access the new user will have to your site. Read more about roles here:
Add existing User page, required inputs are Email and the role, options are Subscriber, Contributor, Author, Editor, and Administrator