Atheists claim themselves to be anti-Christian
No, they don't. Atheists claim that they do not believe in the supernatural. That is all. Also, learn spelling and grammar, please.
yet they follow beliefs that arose from Christianity(i.e. current idea of God,
This is because atheists tend to live in countries where the predominate religion is Christianity. Because it is primarily Christians who seem to argue against atheism, we tend to respond to them the most.
humanism,
Humanism is the belief that humans can control their own destinies without the aid of gods. How is this Christian, exactly?
individualism
Christianity teaches that one must submit oneself to God, and that it is important to take care of the community, even over yourself. This is not individualism.
and even rationalism).
Christianity teaches that it is more important to accept what the Bible teaches than to think for yourself. This is not rationalism.
And rather than going in the direction of truth they have gone in the exact opposite direction.
Hehe. Okay. If you say so.