As long as you embed facebook photos (i'm talking only about the iframe version in this context) the solution described in Embedding facebook post on responsive website is fine.
But the quesion is: how to make a real facebook post embed responsive? example iframe:
<iframe src="https://www.facebook.com/plugins/post.php?href=https%3A%2F%2Fwww.facebook.com%2Fmashable.tech%2Fposts%2F10153931394037919&width=500" width="500" height="482" style="border:none;overflow:hidden" scrolling="no" frameborder="0" allowTransparency="true"></iframe>
please note: i'm not able to use the JavaScript-SDK version, have to use the iframe.