Purpose <p>Nurses play a crucial role as caregivers for cancer patients and providing spiritual care has become an integral part of their responsibilities. However, cancer patients’ spiritual needs are often overlooked in clinical practice. This study aimed to develop and validate a spiritual care e-book for women with breast cancer undergoing chemotherapy.</p> Methods <p>We developed a spiritual care e-book, Healing Light, for women with breast cancer undergoing chemotherapy and used the Fuzzy Delphi method for content validation. Two experts in clinical, two experts in nursing, one expert in education, and three experts in the spiritual care field participated in the study and evaluated the consensus of the e-book content using a standard questionnaire. The obtained data was analyzed using Microsoft Excel, including calculations of averages and formula-based computations.</p> Results <p>Healing Light comprises six sections, each covering specific topics on spiritual theory, practice, and reflection. The content validation showed that the spiritual care e-book has gained expert consensus with all items meeting the threshold values (d) ≤ 0.2, experts’ agreement rate above 75%, and the fuzzy score (Amax) ≥ 0.5.</p> Conclusion <p>Spiritual care faces many challenges in breast cancer practice, including unmet needs, limited resources, and a lack of knowledge about spiritual practices. Healing Light was designed to address these gaps in the Chinese cultural context. As a user-friendly, bilingual, and expert-validated self-management tool, it is intended to serve as a resource that may provide breast cancer women with spiritual care guidance and support during a challenging period in their treatment journey, potentially promoting spiritual health and quality of life.</p>