Il le faut = It must be so.
Il fallait voir comme il était content = You should have seen how happy he was.
Peu s’en fallut qu’il ne fût reçu = He was all but received; He failed for a few marks.
[Latin: Haud multum abfuit quin....]
C’est un homme comme il faut = He is a perfect gentleman.
C’est un homme comme il en faut = He is one of the right sort.
[Sometimes in bad sense: He is the sort of man we want to do that dirty work.]
C’est un homme comme il en faudrait beaucoup = I wish more men were like him (because of his straightforward or courageous nature).
S’il n’est pas un fripon, il ne s’en faut guère = If he is not a rascal, he is precious near it.
Il s’en faut beaucoup que l’un ait autant de mérite que l’autre = There is a great difference in merit between the two.