What we believe as individuals and communities is significant. Sometimes what we say we believe and what we believe that we believe is not what we actually believe.
For example, I might say that I believe in "justice for all," and even believe that I hold this belief, but if I don't in fact engage in any actions that provide evidence that I have this belief, one likely explanation is that I simply don't in fact believe in justice for all. If this were one of my actual beliefs, an observer of my life should be able to discern that I believe this by how I live--how I spend my time and money, for example.
This holds true for all of our beliefs, including the following possible examples:
-true happiness requires good character
-God does not exist
-intellectual virtue is important
-honesty is a virtue
-I should see the interests of others as more important than my own
-The quality of my family life is more important than having a successful career
These are just some possible things that we might think we believe. A worthwhile exercise would be to reflect on how we spend our time, money, and energy in a typical week. Do our actions reflect what we say we believe? If so, great. If not, why not? Perhaps we don't really believe what we think we believe.
It is clear that we cannot directly control what we believe. For example, if someone offered me one million dollars on the condition that I believe that I will develop superpowers in the next 5 minutes, I would not be able to do so. I could claim that I believe it, I could want to believe it, but I could not in fact make myself believe it because there is no evidence for this and much evidence against it.
However, we still can exercise some control over our beliefs. I hold to a view called indirect doxastic voluntarism. This is a fancy bit of jargon which in non-technical language simply means that we do have indirect control over our beliefs. Blaise Pascal, the French philosopher and mathematician, advocates something along these lines with respect to belief in God. While we cannot will such belief into existence, we can do certain things (read Scripture, attend church, practice certain spiritual disciplines) that in his view would likely generate belief. Or consider a different and contemporary example. A senator may be undecided with respect to whether or not we should repeal healthcare reform. In order to come to a belief about this, she might study the issues, examine the current state of health care, and consider other relevant evidence. Then she may come to believe in a particular healthcare policy.
In the realm of personal ethics, I might wonder if I really believe that virtue is necessary for true happiness. I want to believe this, but if I'm honest I may not believe it at all, or at least not as strongly as I would like. To remedy this, I consider arguments for and against this claim, study the lives of moral exemplars and their vicious counterparts, think about when I have most flourished in my relatively short life, and then find that I do in fact believe, or believe more strongly, that one must be virtuous to be genuinely happy.
Finally, for all of the influence of postmodernism on contemporary culture's view of truth and knowledge, human beings still generally seek to live by the best available evidence in their everyday lives. Not always, to be sure, but generally. We drink water rather than gasoline, sit in cars rather than lie down in front of them, and so on. There is a vast realm of human life in which we receive, consider, and respond to knowledge about the world. I think that if we give more focused care and attention to our beliefs about values, then our lives, the lives of those close to us, and perhaps others beyond our immediate circle will be better for it.