One of the most elegant Lutheran churches in Berlin, perhaps the world, is the Berliner Dom. It is located on Spree Island, nestled among several museums and a park. Originally a Dominican church started in 1465, it became a Lutheran church in 1539. It was heavily damaged in WWII. Although the Sermon church finally re-opened in 1993, the final touches to the dome were not complete until 2002.
I briefly visited the front of the church in 2014 with our Luthertour group. If you have several days in Berlin, the cathedral and museums would be a fantastic way to see some beautiful art and architecture.