When Ludger was forced to leave by the Saxons during their persecution of Christians, he called on Bernlef to evangelize to the Frisian people and baptize infants who were likely to die shortly.

[4] According to W. Moll's Kerkgeschiedenis van Nederland vóór de Hervorming ('Church History of the Netherlands before the Reformation'), Bernlef and his wife resided in Holwert near Dokkum and traveled during the winter months to sing songs where he was held in high esteem by listeners.

[5] Over time, Bernlef had become blind and his wife invited Ludger into their home as he passed through Holwert to proselytize, hearing of his good works in the south.

[8] After regaining his sight, Bernlef learned to play the Psalms on his harp from Ludger, forgoing the bellicose poetry from his earlier days and evangelizing to the Frisian people.

[9] When Ludger was expelled from the area by the Saxons, he charged Bernlef with continuing the evangelizing mission and the baptism of believers, particularly baptizing children who were in poor health and likely to die.

For example, Moll writes that Bernlef "was a welcome guest on winter evenings far and wide by free commoners in the area", but Acquoy cites the original Vita Sancti Liudgeri, which only holds that he was held in high esteem by his neighbors.