Its impossible not to _________________ faith in the turbulent times like these.

The correct answer is 'lose'. 'It's impossible not to lose faith in the turbulent times like these' correctly uses 'lose faith', which means to stop believing or trusting in something. 'Lose' is the correct spelling (lose vs. loose are commonly confused). 'Lose' is a verb meaning to fail to keep or cease to have. 'Loose' is an adjective meaning not tight. 'Loosen' is a verb meaning to make less tight. 'Lost' is the past tense of 'lose' but doesn't fit the infinitive structure after 'to'. Note: The sentence has a typo - 'Its' should be 'It's' (contraction of 'it is').