Celsus
Celsus, a philosopher who is thought to have probably lived somewhere in the latter part of the second century A.D., and who wrote an attack upon Christianity, our sole knowledge of which attack is derived from a criticism upon it by Origen. who was appointed by Ambrosius to examine and refute it. His method of doing this was to quote the passages at length, and examine them in detail, and thus he gives us a more or less clear idea of Celsus's work. Celsus is thought by some to have been identical with a Celsus who was an epicurean and the friend of Lucian, but this seems improbable, since this Celsus speaks contemptuously of Plato and his school, whereas our Celsus was distinctly Platonic in his doctrines."
His attack upon Christianity resembles in many points the criticisms of the present day. In the first part he criticises it from the supernatural point of view, as it might present itself to the few whom he introduces, and into whose mouth he puts his criticisms, and endeavours to show its inherent improbability, if not impossibility. In the second part he criticises it from a philosophical standpoint, and tries to demonstrate that it is unphilosophical, unwise, illogical in the inconsistency of its spiritual and anthropomorphic aspects, and absurd in supposing that God cares more for the few than the many, or more for one part of creation than another.