While Christians know that they are justified by faith, Jesus still taught that men are judged by works. Parables in Matthew 7 and Matthew 25 give examples of this. Matthew 7 teaches that there will be those who do great things, but Jesus will say that he never knew them. Matthew 25 teaches that basic acts done for "the least of these" have a much greater importance than we realize.
For the Right Reasons
Good Deeds are the Fruit, not the Root
For All People
"Preach the Gospel at all times, and when necessary use words." - St. Francis of Assisi