Holger's letters home described his enthusiasm for Aristotelianism and Gnesio-Lutheranism, which caused concern from his father, who firmly supported Melanchthonian Lutheranism.

[2] He maintained an interest in theology throughout his tenure in government service and initially supported Hans Poulsen Resen's endeavours to enforce religious uniformity.

[6] During the reign of Christian IV, Rosenkrantz led a church movement, influenced by the piety and practical spirituality in works by Johann Arndt.

Initially, he supported Hans Poulsen Resen's efforts to enforce religious uniformity; but experienced a spiritual crisis around 1620, leading him to temporarily withdraw from public life.

[1] His commitment to theology and education became so ardent that he relinquished his fief and retired to Rosenholm, where he fully immersed himself in his studies and Christian life.