Tech billionaire Peter Thiel recently warned that Swedish activist Greta Thunberg and critics of technology or artificial intelligence are “legionnaires of the Antichrist” in private lectures on Christianity that connected government oversight of Silicon Valley to an apocalyptic future, according to recordings reviewed by The Washington Post.

In the four, roughly two-hour lectures, which began last month and culminated Monday at the Commonwealth Club in San Francisco, Thiel laid out his religious views to a sold-out audience told to keep the contents “off-the-record,” according to an event listing. He argued that those who propose limits on technology development not only hinder business but also threaten to usher in the destruction of the United States and an era of global totalitarian rule, according to the recordings.