You would have to have some pretty good empirical sources of knowledge to start with but even then how far would you get, for instance, trying to teach evolutionary knowledge to creationists?
If you were to learn everything there is to know here on Earth, then which world have you determined to be lacking this knowledge, and how do you propose to execute your plan without imputing ignorance, thus causing offense.
I will teach people that the sky is blue. If that offends somebody, and it surly will, so be it. The JOB is to teach - NOT to insure that people learn.
To help teach the world knowledge you might have to encourage people first of all, to exercise their brain and be suitably fit to separate knowledge from misinformation.