Yes, you are what you say. I know I've said before that actions matter much more than words, and I still believe that. I promise a full blog post on that later, but in brief, my thoughts on this are that you can profess to believe something until you're blue in the face, but it's your actions that will both matter to others and that will prove what you truly value the most. However, words can be crucial in other ways.
What I'm thinking of right now is how our words can shape our attitudes. Yes, our words express our attitudes, but like many things, there is a complex feedback loop of interdependence. We cannot easily just change our feelings or attitudes, but we can go out of our way to say something considerate even when we're not feeling considerate, and this has been proven to temper one's attitude.
This occurred to me when having to deal with someone whom I love very much, but nonetheless I know that I still sometimes have trouble being patient with them. At my worst I sometimes complain under my breath about them, or to a few trusted confidantes, but I also try very hard to express sympathy and understanding for them out loud, either to myself or to my confidantes. I do this to remind myself that they are not just a problem for me, they are a person with problems of their own with which they have to cope. Although their actions sometimes bother me, and I believe actions are much more important than intentions, on those occasions I try to remind myself out loud of the good in them, because their actions are not under my control, and so at those times I need to find a way to think of them with sympathy rather than frustration.
Research has proven that the act of regularly turning up the corners of your mouth as if smiling can actually improve attitude. So while in the end it is your actions that matter much more than your intentions, you can make it easier to act in the way you want by using small actions or even the right words to help shape your attitude and intentions.