how to render a welcome page in page--front.tpl.php I have a template page--front.tpl.php. It contains all different stuffs and a welcome message, wrapped in a div container. Since, I want it to be editable, I created a new basic page called 'Welcome message'. It opens in a separate node 'welcome-message'. 

Now I want this to be rendered in page--front.tpl.php in given div container. Any suggestions?
Login as admin to the site, visit "admin/config/system/site-information" , scroll down to find setting for for front page and then form "Default front page" set the node relative path to be used as default front page that looks like "welcome-message" in your case. 

with the above process you have informed drupal to use the node you have created as front page.

Now remove the hard-coded page front template you have created before as "page--front.tpl.php" because it will be used over the node till its present there.

clear your caches.