The research of Merz is focused on the historical Jesus. She also investigates the Pauline trajectory on the edges of the canon. The intertextual dialogue between documents that became part of the New Testament (e.g. Gospels, Pastoral Epistles) and documents that became apocryphal literature (e.g. Apocryphal Acts) is studied as part of the transformation of sources of early Christian faith into canonical documents. Roukema studies the biblical interpretation of the Church Fathers and prepares a publication on the patristic interpretation of the Greek translation of the Book of Micah and for the series "Novum Testamentum Patristicum" he will write a volume on the patristic interpretation of 1 Corinthians.