We all know that words, without deeds, are dead. However, deeds without words are also dead. Consider the following:

Let's say I have a neighbor, and I want to "preach Christ" to him using my deeds. I greet him over the garden fence. I invite him and his wife round for dinner, where I show them the best hospitality of which I am capable; I explain that I am a Christian, but make no attempt to shove the gospel down his throat. Noticing that his garden could use a bit of work, I offer him my lawnmower, which he accepts, and eventually, through repeated usage, breaks. I do not complain, or ask him to replace it; I replace it myself, and continue to allow him to use it whenever he sees fit. I help whenever I can. In all things, I seek to display unconditional kindness towards him, and to love him as I love myself. Eventually, he dies.

Now what have my actions preached to him? They have preached that Christians are people who do good things for their neighbor. They have preached that niceness, and kindness, and morally upright behavior are what make you a Christian. In short, they have preached justification by works. Your works have indeed "preached" something. But it isn't the gospel.