I was searching for a good Martin Luther quote for Advent. I found a quote I liked in one of Luther's Advent sermons although the subject matter is not dealing especially with Advent. I liked it so much I decided to post it though:
Here you must with all diligence beware of taking offense. Who stumbles at Christ? All that teach you to do works, instead of teaching you to believe. Those who hold forth Christ to you as a law-maker and a judge, and refuse to let Christ be a helper and a comforter, torment you by putting works before and in the way of God in order to atone for your sins and to merit grace. Such are the teachings of the pope, priests, monks and their high schools, who with their masses and religious ceremonies cause you to open your eyes and mouth in astonishment, leading you to another Christ, and withholding from you the real Christ. For if you desire to believe rightly and to possess Christ truly, then you must reject all works that you intend to place before and in the way of God. They are only stumbling blocks, leading you away from Christ and from God. Before God no works are acceptable but Christ's own works. Let these plead for you before God, and do no other work before him than to believe that Christ is doing his works for you and is placing them before God in your behalf.
In order to keep your faith pure, do nothing else than stand still, enjoy its blessings, accept Christ's works, and let him bestow his love upon you. You must be blind, lame, deaf, dead, leprous and poor, otherwise you will stumble at Christ. That Gospel which suffers Christ to be seen and to be doing good only among the needy, will not belie you.
-Martin Luther, in his sermon for the 3rd Sunday of Advent in his Church Postil