It may be prudent first to check what we mean by "rational". I've taken here the first definition from the Oxford English Dictionary:thedistillers wrote:1) Human beings aspire to be happy. The logical consequence of atheism is despair and nihilism. If atheism is true, there is no reason to care about truth, or anything else, so even if God doesn't exist, it's more rational to believe and hope God exists, to live a happier life.
2) The universe had a beginning. It is irrational to believe a universe can start to exist without a cause, for ex nihilo nihil fit. Only what we call "God" can be the cause for the universe, for the cause of the universe has to be personal and immaterial. Therefore atheism is irrational.
3) You can only make sense of the universe if it behaves in a predictable way. If atheism is true, there is no rational reason to believe the universe will continue to behave in a predictable way. We cannot make sense of the world we live in if atheism is true. Therefore atheism is irrational.
4) There is no rational explanation for the Gospel accounts, unless Jesus really rose from the dead. Only God had the power to raise Jesus from the dead. Therefore God exists, and atheism is irrational.
5) Atheists can't even prove their position, using evidence and logic. Therefore atheism is irrational.
Rational (adj): Having the faculty of reasoning; endowed with reason.
I would say that atheism is clearly based on reasoning. I find it an internally consistent world view, albeit one to which I no longer subscribe (due to a clash with subjective experience). I also find faith is reasonable and internally consistent, albeit partly depending on subjective experience (a view may be reasonable and subjective at the same time, so long as we acknowledge the subjective aspects).
I think there is a problem in saying atheism is irrational, as you are then forced to engage with a straw man rather than atheism as it actually is, which is clearly a reasoned position that is internally consistent.