Trust is an amazing thing...
It's a little like Faith. It makes you believe even if everything around you tells you not to. Trust is that little extra bit of good faith and good will that you extend towards someone because that person means something to you and you believe that the person will never do anything to hurt you. It gives you a sense of security in a time of chaos.
It's easy to say you trust someone. But the truth is, trust often lies only on the surface. It's only when you can rest easy at night without the voices whispering and making you toss and turn in bed, that you can say there really is trust. Trust is when the person you love says someone else is gorgeous/beautiful and you don't feel a stab of jealousy because you know that you mean more to the person.
Trust is not an easy thing to give if you have not been proven that your trust should be given.