go through fire and water

Referring to ancient ordeals. Presumably Psalms 66:12.

go through fire and water (third-person singular simple present goes through fire and water, present participle going through fire and water, simple past went through fire and water, past participle gone through fire and water)

1. (dated) To undertake any amount of trouble or risk to achieve some end.

• go through hell
• go to hell and back

• “go through fire and water”, in Cambridge English Dictionary, Cambridge, Cambridgeshire: Cambridge University Press, 1999–present.
• “go through fire and water”, in Collins English Dictionary.
• “go through fire and water for somebody” in Longman Dictionary of Contemporary English, Longman.