Basic Shortcode Not Rendering Inside Section

At this point, I'm just testing a very simple shortcode to bring some text on a full width banner section on the homepage. Eventually it will be used to bring in custom code for styling Advanced Custom Fields.

URL - http://staging.wheelsnwaves.com/

Here's the code I have in my child theme's functions.php file:

function test_function() {
	echo "TEST";
}
add_shortcode('test', 'test_function');

The shortcode prints the text, but it ends up outside of the section. Thoughts?