Finder does not launch from Dock unless I click on the icon and New Finder Window I am using a Mac mini 2010 with MacOS Sierra 10.12.6.

Today, I deleted and re-created my Finder preferences after the originals became corrupted.

Clicking on Finder (the blue smiley-face square) within the Dock did not work unless I went to Open New Finder Window.

The Desktop works, no issue there.

Is there a way within MacOS Sierra to get it to open automatically by clicking on the icon, like with other apps in Dock, such as Firefox or Terminal?

Any help is much appreciated.
Tick the second option listed in Mission Control Preferences. "When switching to an application, switch to a space with open windows for the application."