Faith (in God) says that when everyone and everything around us says God is not present or caring, knowing his Word and his promises, you know that he IS present, he IS caring, he is working in your life.
Being faithful then is taking this knowledge and putting it into action. Knowing God is present and so speaking with him and waiting to hear. Know God cares and so meanwhile caring for others. Knowing God is working and so being an instrument through which his work can be done. Being faithful is continuing in knowing God.