The essential content of revealed philosophy is viewed by the Apologists (see A, B) as comprised in three doctrines.[420] First, there is one spiritual and inexpressibly exalted God, who is Lord and Father of the world. Secondly, he requires a holy life. Thirdly, he will at last sit in judgment, and will reward the good with immortality and punish the wicked with death. The teaching concerning God, virtue, and eternal reward is traced to the prophets and Christ; but the bringing about of a virtuous life (of righteousness) has been necessarily left by God to men themselves; for God has created man free, and virtue can only be acquired by man's own efforts. The prophets and Christ are therefore a source of righteousness in so far as they are teachers. But as God, that is, the divine Word (which we need not here discuss) has spoken in them, Christianity is to be defined as the Knowledge of God, mediated by the Deity himself, and as a virtuous walk in the longing after eternal and perfect life with God, as well as in the sure hope of this imperishable reward. By knowing what is true and doing what is good man becomes righteous and a partaker of the highest bliss. This knowledge, which has the character of divine instruction,[421] rests on faith in the divine revelation. This revelation has the nature and power of redemption in so far as the fact is undoubted that without it men cannot free themselves from the tyranny of the demons, whilst believers in revelation are enabled by the Spirit of God to put them to flight. Accordingly, the dogmas of Christian philosophy theoretically contain the monotheistic cosmology, and practically the rules for a holy life, which appears as a renunciation of the world and as a new order of society.[422] The goal is immortal life, which consists in the full knowledge and contemplation of God. The dogmas of revelation lie between the cosmology and ethics; they are indefinitely expressed so far as they contain the idea of salvation; but they are very precisely worded in so far as they guarantee the truth of the cosmology and ethics.