But the deepest point in his criticism of Christianity is not the scientific with respect to history, or the philosophy with respect to the idea of incarnation, but it is something else: it is a really religious feeling, namely when he says that the demonic powers which as Paul says have been conquered by Christ, actually rule the world..–..the argument which you can hear everywhere in our time, and the world has not changed, since the beginning of Christianity. But Celsus adds: There is no sense even to try to overcome these powers; they are the real rulers of the world.
Therefore, one should be obedient to the Roman rulers on earth because they have at least reduced the power of the demons to some extent – which is also a Pauline idea. They have established a certain order in which the demonic forces are limited. Therefore the Roman emperors, however questionable they may be personally, must be obeyed and must receive veneration, for through the obedience to the orders of this world, to the necessities of law and nature, Rome has become great.
What the Christians do is to undermine the greatness and the glory which is Rome, and in doing so they undercut the only power which is able to prevent the world from falling into chaos and a complete victory of the demons. This was not an easy attack, but a very serious one, and one which has been heard again and again in all Church history. And you can understand that Christians arose who had the same philosophical education as Celsus had, and who tried to answer these attacks. This is the meaning of the apologetic movement, out of which theology has arisen.
Now these people didn’t refute historical criticism very much, because in the moment in which you go into this, then whether you defend one position or not, you cannot defend all positions. When you accept the method, then all the difficulties arise which we have experienced in the history of Protestantism during the last 200 years, and which are alive today as they ever were. Think of the famous discussion about the demythologization of the New Testament, where we have exactly the same problem.
So these Apologists didn’t go into this, but they tried to answer the philosophical criticism, and did it in a way which tried to show three things. This is the way every apologetic has to work. First of all, if you want to speak with somebody meaningfully, there must be a common basis, some mutually accepted ideas. This truth common to Christians and pagans must first be elaborated. If there is nothing in common between them, no conversation is possible and no meaningful addressing oneself to the pagans is possible. It always must be supposed – and this is a rule for all Christian missionary work – that the other one understands what you say, but understanding is partly participating. If he speaks an absolutely different language, then no understanding is possible. So the Apologists showed that there is something in common.
Secondly, they must show that in the actual ideas of paganism, there are defects. There are things which contradict the ideas even of the pagans themselves. There are things which have been criticized for centuries, even by the pagan philosophers. One shows the negativity in the other one, as the second step of apologetics.