In Germany, spring is dotted with public holidays that have their origins in Christian tradition: Good Friday and Easter , which celebrate the crucifixion and resurrection of Christ; Ascension, commemorating Christ's ascent into heaven; and Pentecost, considered the birthday of the Christian Church. Also known as Whitsun or Trinity Sunday by some religious traditions, it marks when the Holy Spirit is believed to have descended upon the Apostles of Jesus, Mary and other followers of Christ, 50 days after Easter — hence the name, which comes from a Hellenistic Greek word meaning "50th." Though the holiday is important for Christians, it has its roots in Judaism .…