The 38th chapter of the Revival of the Religious Sciences, this treatise follows on from Al-Ghazali on Intention, Sincerity & Truthfulness. Here, Ghazali focuses on the different stations of steadfastness in religion (murabaha), vigilance and self-examination being its cornerstones. As in all his writings, Ghazali bases his arguments on the Qur'an, the example of the Prophet, and the sayings of numerous scholars and Sufis. As relevant today as it was in the 11th century, this discourse will be of interest to anyone concerned with ethics and moral philosophy.