As about 100 Baptists from around the world prepared for worship Sunday morning at the start of the Baptist World Alliance’s 2018 annual gathering, they left behind the bustling city of Zurich, Switzerland, and hiked up a quiet hillside near the community of Bäretswil about a half-hour drive away. Once up in the cave hidden back in the woods off a dirt path, their words echoed through the chamber — the same words that have bounced off those dark walls for hundreds of years.