While he was a professor at Wittenberg University, Luther devised this seal which he declared was meant to be "expressive of his theology." The following explanation is the gist of a letter written to his friend, Herr Spangler, town clerk of Nuremberg, Germany.
The first thing expressed in my seal is a cross, black, within the heart, to put me in mind that faith in Christ crucified saves us. "For with the heart man believeth unto righteousness." Now, although the cross is black, mortified, and intended to cause pain, yet it does nor change the color of the heart, nor destroy its nature- i.e., does not kill, but keeps alive. "For the just shall live by faith," -by faith in the Saviour.
This heart is fixed upon the centre of a white rose, to show that such faith yields joy, peace and comfort such as the world cannot give. The rose is white, not red, because white is the ideal colour of all angels and blessed spirits.
This rose, moreover, is fixed on a Heavenly blue background, to denote that such joy of faith in the spirit is but an earnest beginning of heavenly joy to come, as anticipated and held by hope, though not yet revealed.
And around this groundbase is a golden ring, to signify that such bliss in heaven endures forever, and more precious than all earthly joys and possessions, even as gold is the most precious of metals.
May Christ, our dear Lord, be with you unto eternal life. Amen.