Here is the answer to your question.
Suppose I want to do a search for a post containing 5 specific words in a phrase. How do I do a search for posts containing all 5 words together rather than for 5 individual words?
Since you specified the word post(s) twice in your question, it's obvious that you meant the search feature here on this site.
Quotation marks will not work.
Notice just above the window where you enter the five words you want to use to narrow your search. There is a statement that says, Messages containing Any of the following keywords. Next to the word "Any" is a downward pointing arrow.
Click on the arrow.
Select "All".
This will narrow your search to only posts that contain all five of the words, although the search result will include all posts that contain all five words, no matter in which sequence the words appear or whether the words are consecutive or separated by other words.