It may surprise you, but the Roman Catholic Lithuania you see today is only one part of the historical Lithuanian nation. The other one, known as Lithuania Minor, had never enjoyed independence. Until the 20th century it was a part of Prussia and so the local Lithuanians became Lutherans.
At one time the Lithuanians (known there as “Lietuvininkai”) were the majority in a quarter of East Prussia province, but rapid Germanization of the 19th century diluted their stand. The final blow to “another Lithuania” was the Soviet genocide of the 1940s, when most lietuvininkai were either murdered, deported, or chosen the path of refugees together with local German civilians (also Lutheran) who were expelled by the advancing Red Army.
East Prussia was annexed by the Soviets and Poland, then repopulated. What is now Kaliningrad Oblast was swiftly repopulated with Russians, whereas the northernmost part of former Lithuania Minor, so-called Klaipėda Region, was largely repopulated by Lithuanians from Lithuania Major.
Even so, the Klaipėda Region still has red German-style Lutheran churches in many larger towns and while their congregations are long since surpassed by Catholics and Atheists, some 5% of people in these rural areas are lietuvininkai descendants still adhering to the Lutheran faith (down from 91,7% in 1925). Lutheran communities also exist in the major cities, in southern Samogitia (Tauragė area), in some localities near the Latvian border and in western Sudovia.
Unfortunately, the most beautiful Lutheran churches in Klaipėda and their massive spires were torn down by the Soviets after the World War 2. What remains are largely town and village churches built of the iconic German red bricks. They too were looted during World War 2 and closed throughout the Soviet occupation but most buildings survive.
In 1925 the Republic of Lithuania had over 200 000 Lutherans (9% of the population, the largest religious minority at the time). The census of 2001 found 19 637 Lutherans (0,6% of the population). Such a decrease means that while the old network of parishes was partly reestablished after independence, the mass is typically celebrated less than weekly in the reopened village churches.
The Lutheran cemeteries were also looted and demolished by the Soviets. The cemetery in Šilutė left between existence and destruction serves as an unofficial memorial for the losses suffered by the community.