He was a monk of saintly life, employing all the time he could spare from his duties towards others in prayer, contemplation and writing on ascetical and mystical subjects.
He was one of the last, and was perhaps the most precise in language, of those whose written teachings paved the way for Saint Margaret Mary Alacoque and her mission, and helped to prepare the Catholic mind for the great devotion of modern times.
His brothers referred to him as "viri certe integerrimi, devotissimique simul in activa et contempliva vita, ac sacris litteris exercitatissimi.
"[2] The editor of Lanspergius' complete works (1554), described him in the preface as his most worthy teacher within the Carthusian Charterhouse "quondam in nostrae religionis instituto praeceptoris mei dignissimi.
"[3] He also developed a close relationship with his Carthusian brother, Bruno Loher, who recognised his "rigorous asceticism, piety and virtues" while highlighting his perfect submission to authority and chosen way of life shortly before Lanspergius died in his fifties.