One quick, point... nothing much really.

Darwin's Theory of Evolution, well erm.. while taken as green now has *still* yet to be proven. As such while people widely accept this believe to what has happened, it is still only something on a piece of paper and any scientist who believes enough in pure science to try and disprove something in such a way. Well right there would be the biggest flaw in your argument, using something unproven as the basis for your logic.

If you want to actually try to disprove the basis philosophy behind Christianity, then what you'll first have to do is actually backtrack what is the 'real' Christian religion.

Remember what we follow now in general (Catholism / Protestant) are both off-shoots of the original version of the regilion. Both of these new versions have changed when the Bible has been translated or in order to scare people senseless into joining the Church and casting about their penence.
A good example being how Catholism created 'Hell' as an extension to Purgatory, which was originally a case of where you would go for a number of years to make up for your Sins before being 'reborn' to the world, rather than going to heaven. Alot of things have been lost or altered over the years, to make the Church of your favoured Edition of Christianity seem like salvation.

So really your question should start with your research into the matter rather than some base knowlage probably learnt in Sunday School.

I'd be happy to have a well constructed argument about what is wrong with the Origin Theory, provided you actually take the time to construct one. :)