If you paste HTML or JavaScript code in the blogger post, blogger will convert the code into the result but if you want to show your HTML code as it is in the blogger post. Here is the solution.
Just go to blogger settings >> basic >> select post editor >> updated editor >> save settings.
Then go to your blogger post and paste some HTML code into it. After that go to post options >> show html literally >> publish post.
Now you can see HTML code in the blogger post after publishing the post.