This church is far more important in terms of the Reformation than any other in Germany. Here it was that Luther did his primary work as preacher. From the pulpit that was once here, Luther's theology was practices and taught. Copies of his sermons flooded throughout Germany and the western world of Luther's day.

The interior of St. Mary's was remodeled. The pulpit here now is not the one Luther used. However, the altar painting by Lucas Cranach is original and was completed the year after Luther's death in 1546. There are rare paintings around the chancel area behind the altar.