Heaven knows we need never be ashamed of our tears 請問 need 後面直接接be是什麼文法? need 不是要+to嗎?

... need not be worried ...裡的need是助動詞，主要動詞是be，worried是主詞補語。副詞not放在助動詞與主要動詞之間。
... don't need to be worried ...裡的need是主要動詞，to be worried是不定詞片語，當作動詞need的受詞。因為否定，而加了助動詞do，not放在助動詞和主要動詞之間。
need可當助動詞、主要動詞、或名詞用。
need not to be worried的語法錯誤。因為當主要動詞用時，不能直接在後面加副詞not，需要寫成don't need to be worried。

Heaven knows we need never be ashamed of our tears.

"need" can be used as a main verb or a modal verb. "need" is a modal verb in the above sentence, so the main verb "be" must be in its BASE form (ie. bare infinitive).

不需要擔心
是 need not be worried (worried is an adjective here)
= need not feel worried
= need not get worried

或者 need not worry 也可以 (worry is a verb here)

need not be worried / need not worry (modal verb)
don't need to be worried / don't need to worry (main verb)

I don't see a major difference in meaning between them.
They are similar to making an advice or consolation by saying "Don't worry!" or "Don't be worried!"