"Education is an important thing."
Translation:חינוך זה דבר חשוב.
In Hebrew "Chinuch" or חינוך refers to schools as well. We see teachers as providing values like parents. For example in Israel the education system is referred as "מערכת החינוך". "Haskala" or השכלה is the knowledge you gain by participating in school/university. You can say השכלה זה דבר חשוב and it will be fine, it will just have a different meaning.
When there are two nouns on either side of a nominal sentence, then the copula is preferred. In this case, we have the nouns חינוך and דבר. So we would need either הוא or זה copula but it will not accept the former for unclear reasons. Long story short, you would be understood but there are some tendencies with copula use. Whether to use הוא or זה is another matter. I thought that the latter is a little more informal but otherwise interchangeable usually, but I am just a learner. (If there was a noun on one side but an adjective in the predicate of the nominal sentence, then no copula.)