As a principle I have no faith in anything. ("faith must trample underfoot all reason, sense and understanding." - Martin Luther)
But I have developed confidence in certain companies, both first and second-hand confidence.
When I can ... Malkoff Devices, SureFire, HDS, Mag-Lite (hosts) ........ <--- Never had a failure with them yet.
When I must ... Foursevens, Fenix, Zebralight. ........... <--- had light failures and malfunctions with all of these manufacturers.
Never ... Most Asian-manufactured low-quality "high value" lights. <--- would expect imminent failure and malfuction with any of these manufacturers.
I have a diverse collection as far as battery types, and the three there (SF, MD, HDS, ML) do not make good lights in many battery types, such as CR2, AA, AAA ... With some exception of course ... But for those I've had to go with East-Asian manufactured lights of hopefully moderately trustworthy companies.
edit: At one point I had more lights manufactured in East Asia than USA. Many of those have since died, leaving me with more lights manufactured in USA than East Asia.