That kind of matches are what regexps were intended for:

  grep "foo.*bar" hello

Unfortunately, the basic grep syntax doesn't give you an easy way of specifying both orders, so that would have to be something like:

  grep -e "foo.*bar" -e "bar.*foo" hello

You can specify random order in a couple of different ways with Perl-compatible regexes, such as lookaheading the search terms from the end of line marker. But it's not as easy to read as it should be.

With sed instead of grep, and probably not much better, but in a single command:

  cat hello | sed -n '/foo/{ /bar/{ /baz/ p }}'

Keep doing it that way, I'd say. The other replies are ways to do it without chaining grep, but they don't seem any less verbose and definitely are less obvious.