Hide it, not Delete it
If you click on the Edit or Remove button (which appears when you hover over the upper corner of a post in your Facebook Timeline), you are given the option to Hide, or Delete the post. As the action’s label implies, selecting Hide from Timeline removes the post from the Timeline without having to actually delete it.
You can unhide/restore the post by clicking Undo, which appears immediately after you hide it.
Restoring Hidden Posts via the Activity Log
You can restore all your hidden posts in the Activity Log. The Activity Log is “a list of your posts and activity, from today back to the very beginning” (Facebook), therefore this is where you can find all the posts that you’ve hidden in the past. In the contrary, this does not include posts that you deleted.
Click the Activity Log button just below the cover of your Timeline and find the post that you hid. You can see at the right side of each entry the status of the post. Click it and switch the status from Hidden from Timeline to Allowed on Timeline. The post will then be visible in your Timeline once again.