shēn​xìn​bù​yí

convinced

深信不疑 shēn​xìn​bù​yí
convinced idiom
to believe firmly without any doubt; to have absolute certainty about something

深信不疑

duì suǒ shuō de huà shēn​xìn​bù​yí.

I have no doubt about what he said.

Frequency

Movie subtitles
1.94 per million appears in 1% of films
Written text
1.10 per million

Sources

Definitions
CC-CEDICT