This study aims to analyze the teaching strategy of Christian Religious Education (PAK) in supporting the spiritual growth of grade XI students at Private High School HKBP 1 Tarutung for the 2025 Academic Year. The background of this research is based on the importance of spiritual growth as an integral part of the formation of students' faith, character, and spiritual maturity in the midst of the challenges of the modern and digital era. This research uses a qualitative approach with a case study type in an interpretive paradigm. Data was obtained through interviews, observations, and documentation, then analyzed using the Miles and Huberman data analysis model which included data reduction, data presentation, and conclusion drawn. The results of the study showed that the PAK teaching strategy applied was contextual, relational, and participatory, by utilizing discussion methods, reflection on God's Word, joint prayer, assignment of applicable assignments, and teacher examples as a Christian life model. These strategies contribute to shaping the understanding of faith, changing attitudes, and habituating students' spiritual practices. However, there are challenges in its implementation, such as low consistency of students in spiritual disciplines, the influence of social and digital environments, and dependence on teachers in the process of fostering faith. This study concludes that an effective PAK teaching strategy is a holistic, integrative, and centered strategy on the formation of Christian character, which not only emphasizes cognitive aspects, but also spiritual experiences and life examples, so as to be able to encourage students' spiritual growth in a sustainable manner.