1. Science suggests that the universe is 20 billion years old, the Earth is 4.5 billion years old. Despite this Christianity is a very human-centric philosophy. I cannot argue that religion is consistent with science, whether astrophysics or human nature. Religion to me is a repudiation of everything I know. I can disprove every argument you can make about religion.
2. Grand design: The idea that the universe is a miraculous design, so there must be a designer. This ignores the reality that there was no conscious designer for the universe, it developed or unfolded as a result of its nature. i.e. The materials comprising the universe developed as they must, in accordance with their physical properties.
3. Creation. The argument that there must be a God, otherwise who created the universe 20 billion years ago. The origin of the universe is a speculative issue, however I would posit that the universe was never created; that it has always existed. I would assert that every 20 billion or so the universe goes through a 'Big Bang', or sometimes perhaps smaller bangs. I don't think the universe has the uniformity in its evolution as posited by physicists.
4. Motive: A human-centric God as the maker of the universe and humanity is dubious when you consider the requirement for God to be so patient. He would have to wait 4 billion years for the Earth to form, and 20 billion years for the universe to develop before he could have created humanity. It seems more probable that he does not exist, and Christians are ignorant idiots.
5. Causation: The idea of a God defying all the natural laws that drive every other physical entity is another basis for driving a peg through the Christian hypothesis/'scare model'. The Christian philosophy is a repudiation of human nature, as shown elsewhere.
For a greater appreciation the smallness of humanity in the context of the universe watch this video clip. I recommend it not to show how small you are. You are very important to you, and to anyone who values you. You cannot detach the value from the valuer, which it was Christianity asserts. You are not intrinsically good. You are good for reasons....as determined by a thing which has the capacity to value, whether your pet dog, a presidential nominee, or your wife.
Andrew Sheldon www.sheldonthinks.com