Bona fides is my first choice of making friends.
真诚是我交朋友的首选。

In doing this, it requires your bona fides and devotion.
做这件事需要你的真诚和投入。

Mr. Perks questioned them at length to establish their bona fides.
珀克斯先生最后质问他们如何证明自己的诚意。

I mention all this by way of defining my bona fides for the following commentary.
说到这些，只是为了说明我作出下述评论的权威性。

Weapons traders should be required to exercise due diligence to identify and confirm the bona fides of their clients.
应当要求武器贸易商克尽职责, 查明并确认其客户诚信无欺。