Trust is a pretty important factor that plays a positive role in a functioning society. To trust someone basically entails that you can rely on the actions of another person to conform to certain virtues or expectations while basically abandoning your own control over the situation.
Let’s look at two examples of where trust plays an important role. Firstly, you have money to do empirical research. You provide the money to a scientific researcher with a good track record and you ask him to do research on the clinical effects of a certain compound. You trust the scientist to use your money in such a manner that will result in good results. You are basically abandoning your own control over the situation (doing your own research) and transferring control to another. The outcome is unknown, but you trust that it will end in a certain manner i.e. good results.