You use Emacs, you like evil-mode, but when you type :tabnew nothing happens. Install this.

If you’re hooked up to MELPA:

M-x package-refresh-contents
M-x package-install RET evil-tabs

(Alternatively just grab the single evil-tabs.el file and install that in your preferred way.)

Then add (global-evil-tabs-mode t) to your .emacs file, and eval it.