Trust: the "faith" of relationships?

There are numerous reasons I could list on why not to trust someone, but I'm more curious to ponder the opposite: What is it that drives one to take the blind leap of faith and choose to trust another human being? Is it dependent upon the relational dynamic? Is it easier or harder to trust an individual vs. a group entity? Are we more likely to trust others with our secrets, feelings, passions? How much trust do we invest when it comes to trusting someone with our life, fidelity, money?

These are questions I've been pondering since I watched the Martin Scorsese movie "Casino" last night. Throughout the movie, I noticed and found it funny that characters repeatedly (and emphatically) made comments about needing to be able to trust one of the other characters....funny because it's a movie that centers around the mob and  there's major underlying deception going on among multiple characters. As much as they can hold their own in certain situations, the ultimate downfall is that the characters chose to trust when it wasn't in their best interest to do so. And the price for trust? Loss of money, loss of mental sanity, loss of love, loss of friendship, loss of life. With so much at stake, why do they trust? Why do any of us trust?

Perhaps trust is to relationships what faith is to religion....belief in something "higher" or better despite the unknown lurking in the shadows. A yearning for connection on an intimate level (whether with a friend, lover, or spouse) overpowers the risk it takes to trust and the consequences that may unfold as a result of that trust. Could it be that we would rather see the humanity in each other than be jaded and completely closed off? Maybe there's hope for humanity after all. Or so I trust.