Give a chance to everyone, and with time you will see who deserves your trust. Personally, I call it “filtering”. Of course it can be painful, and I hate those filtering and to lose people. But if you want real friends around, whoever shows to deserve your trust can be called a real friend. Good luck! Wishing you to meet just honest and trustworthy people!
The best way to find out if you can trust somebody is to trust them!