But someone will say, "You have faith, and I have works." Show me your faith without your works, and I will show you my faith by my works."
James 2:17-18 (NKJV)
The old saying that "Talk is cheap" comes from the idea that it is easy enough to talk about something, but actually doing that same thing is entirely different. For example, people can talk about making a change in their lifestyle, like people do with New Year's resolutions, and that is easy to talk about. But it is something completely different for that same person to start an exercise routine, start eating better, or break a bad habit. The best thing is when what we say and what we do are the same thing.
Faith is an important subject in the Bible, that is clear. There are many people who are good "faith talkers" but many of these people are just talking about faith with nothing to show for it. Christians will sometimes talk about biblical concepts like walking in love, being generous with their talents or finances, being faithful to church, and following God's plan for their life. But, if you look at what these same people actually do, their works are showing what they really believe, their actions are the display of where their "faith" really is.
So often the problem is that people understand the concept of what they should be doing in their life and relationship with God, but they have not developed in their faith and trust in God and His Word, to the point where their actions correspond with those beliefs. As James said, you can see what people really believe by watching the things that they do. We are not supposed to live a life based solely on good works, but our "good works", as a demonstration of what we actually believe, are something that should be seen in the life of every Christian.