The Seal of Martin Luther was designed by Martin Luther himself. He explained his design in the following words:
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, it does not change the color of the heart, does not destroy nature -- i.e., does not kill, but keeps alive. "For the just shall live by faith," -- by faith in the Savior.
But this heart is fixed upon the center of a white rose, to show that faith causes joy, consolation and peace. The rose is white, not red, because white is the ideal color of all angels and blessed spirits.
This rose, moreover, is fixed in a sky-colored ground, 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 ground base is a golden ring, to signify that such bliss in heaven is endless, and more precious than all joys and treasures, since gold is the best and most precious metal. Christ, our dear Lord, He will give grace unto eternal life.
Amen