Jörg Frey and Craig R. Koester (eds.), Signs und Discourses in John 5 and 6. Historical, Literary and Theological Readings from the Colloquium Ioanneum 2019 in Eisenach, WUNT 463, Mohr Siebeck, Tübingen 2021, 386 S., ISBN: 978-3-1610006-7 - Klein, Hans (Review of ecumenical studies, 2021)