I like that this topic is raised today coz I was having a conversation with a friend and we talked extensively in trust as it cuts across all aspects of our lives, but we spoke extensively with regards to marriage and broken homes.
It was a fun conversation as he was able to convince me on the reason he has lost trust in humanity. According to him, he has been stabbed a million times in the back (I wonder why he is still alive though...lolzz).
Well for me I don't trust anyone as well but what I am very good at doing is giving people the benefit of doubt...I will let you prove to me how trust worthy you are or how untruat worthy you are.
It's good to give people a chance even though you don't trust them. Give them that chance and watch them closely and with that you will be able to know those you can trust and those you can't with the outcome of their actions.
You will know who is likely to act accordingly and who is not. :)