What is the ruling on receiving treatment from a skilled Christian doctor?

The fundamental principle is for a Muslim to seek out a trustworthy and skilled Muslim physician. If such a physician is not available, or if a non-Muslim is more knowledgeable about their illness, then there is no harm in consulting them. This is based on the general permissibility of interacting with the People of the Book, provided it does not constitute loyalty to them. It is important to note that if a Christian physician advises abandoning fasting or praying while seated, their advice should not be accepted unless it is corroborated by Muslim physicians. It is recommended to supplicate: "Indeed, adversity has touched me, and You are the most merciful of the merciful."