Question

I say we must not speak the unspeakable name of love to the windless stars, but hold it like a candle flame and whisper hope, each to another, ecstatic in the gathering dark. —Anonymous (with permission) 3. What simile is used in this poem? 4. What is the main idea of this poem

Answer 1

3. hold it like a candle flame. A simile is a comparison that uses a word like the word like.
4. I would say that the main idea of the poem is hope, but that is totally up to you.

Answer 2

"... but hold it like a candle flame..."

The main idea of the poem is up to whoever, as poems are very subjective, however what I understand, the poem is about a forbidden love.