Follow Below Step How to add recent Post and comment using Feed.
1.Login Into Your Blog.










2.On Dashboard click Design ►Page Element









3.Click Add A gadget ►Feed







4.Insert Feed URL ► Continue ► title ► Recent Posts ► Save


 




Feed Url for Recent Post

Feed Url for Recent Comment

Example:

After that Click Continue and make tittle For recent Post And Comment.


5.You can tick Item dates and Item sources/authors if you want to show it.After
that save it.