I dont know about anyone elses experiences, but sometimes Allah has shown me through small signs who people realy are.
Although they have been deceitful and dishonest to me, in my naivety I make excuses for them, I hide the wrong that they are doing when really I should for once stand up for justice and face them head on, demanding explanations. But I choose not to. Sometimes its better to make excuses for you fellow muslims and allow Allah to do the rest. If they really are deceiving you, Allah will show you, and then its up to you, whether you want to foolishly carry on blindly, or be strong enough to walk away for good. Each time I gave someone a chance and made an excuse for them, some how strangely Allah showed me in ways, some ways that were purely accidental, that these people have not changed and are still dishonest. Its up to you to take notice of the sign Allah sent you, to hear Allah and be strong. There are times where we ask Allah to show us the truth, to show us which direction to turn, and when He shows us we become unhappy about it, we are in denial and we carry on making bad decisions that never will benefit us.
Deep down we all know the people and the paths that are harmful to us and the ones that will benefit us and bring us closer to Allah. We know but we are not strong enough to listen to our own instincts. Be strong enough to walk away, with the full belief that Allah will reimburse you with something so much more fitting or that those people will return to you, when they have finally realised, that they can hide their dishonesty from you - but not from Allah.
And of course the same goes for the opposite. If a person is sincere, pure and genuine, you will surely see it. Allah will not veil this from you. You will know in your heart who beautiful people are, and when you find them you should not let go of them, for they can only make your life beautiful. And you should fear that you should never hurt them, be good to them, and know, that Allah is with them, and will surely show them how ugly you are, if you are not sincere from within.
I ask Allah to help me see things as they truly are, and to show me people for who they truly are, and for the strength to base my decisions on this reality.