That atheism is not rationally justified

[Dolorian]

Hope and happiness have no bearing on what is true. Their argument is reduced to "this gives me hope and happiness; therefore, it is true."

Yes, that's exactly what it boils down to. Also, I don't see why one should agree with the whole "reason is inadequate" to decide on the question to begin with. Seems quite arbitrary when applied to God. If you can't appeal to evidential or philosophical arguments for the existence of God to demonstrate things, then why should it be considered to begin with?

Yes, science and christianity both make assumptions. However, the assumptions that science makes are far less than what christianity makes. Also, science produces verifiable results. Just because science makes assumptions does not mean it is on equal footing to christianity.

Of course, they are by no means on the same footing; even tho Christians would love them to be.