Complex sentence: A Protestant group analogous to the New Catholics, the Friends of the Light, joined with the German Catholics in 1849, forming the Freireligiöse ("free-thinkers") communities.
Split into simpler sentences: A Protestant group analogous to the New Catholics was the Friends of the Light. In 1849, these two groups combined to form the "Freireligiöse" ("free-thinkers") communities.