Diligence is an adverb, which should be extended to "hard work", but "land" is omitted. Education is a verb, and it is reasonable to modify verbs with adverbs. Of these four words, there is no mistake in principle, which is completely reasonable.

If it is wrong to say that "we are moved by the teacher's hard education", it is a sick sentence. If you want to change it into a correct sentence, you can change this sentence to "The teacher's hard education makes us moved", or put it another way: "The teacher's emotional education makes us moved".