paragraphs tag in post contents

Hi,
I have some trouble with the paragraphs tags in post contents.

Using <?php the_content(); ?> the <p> tags show up in the published webpage.

But when using <? echo get_post($s_ID)->post_content; ?> they are not shown.
(I use this method to add other posts to a main post.)
I looked at the Mysql post_content field. There seems not to be any <p> tags.

How must I modify the second method to get the <p> tags ?

best regards
glenn