Trust is what makes a relationship, lack of the same breaks it...
Trust is a thin cord, yet if it exists, can withstand unimaginable amount of pull or pressure. It can change lives, can make someone do things not believed to be possible. However, if we are careless, it can snap at the slightest mistake and it's never the same. It can be re-established but there will be a knot in the cord, which takes a toll on the relationship. Its never what it was. Hence, we should nurture this particular aspect to ensure the strength of the relationship.
Bottom line, take care of the trust factor in a relationship to live it, else it will slip out of the hand like dry sand does from your hand...
