Neil Shenvi's Three Paradoxes of Atheism is worth chewing over.
The whole article is worth reading. This is his conclusion:
In conclusion, I want to summarize the paradoxes I believe are inherent to the atheism.
- Truth-seeking. If a truth-loving God doesn't exist, then truth-seeking is neither intrinsically good nor morally obligatory. Therefore, paradoxically, the Christian has grounds to urge all people to seek the truth and to claim it is their moral obligation to seek the truth whereas the atheist has no grounds to urge others to seek the truth or to claim it is their moral obligation to do so.
- Moral reflection. Suffering and evil in the world is so prolific and horrendous that we instinctively avoid thinking about it to preserve our happiness. If Christianity is true, then all suffering and evil will one day be destroyed and healed. If atheism is true, suffering and evil are pointless and will never be rectified. So, paradoxically, a Christian gains the emotional resources to reflect honestly on suffering by reflecting on reality (as he perceives it) while an atheist gains the emotional resources to reflect honestly on suffering only by ignoring reality (as he perceives it).
- Moral motivation. If Christianity is true, then all of our moral choices have tremendous, eternal significance. If atheism is true, then none of our moral choices have any eternal significance. So, paradoxically, the Christian gains the motivation to act morally by reflecting on reality (as he perceives it) while the atheist gains the motivation to act morally only by ignoring reality (as he perceives it).
None of these observations imply that atheism is necessarily false or that Christianity is true. But I hope that they do cause atheists some serious reflection. At least in these three areas, there is a conflict between the general perception that atheists live a life of realism, facing the truth about reality squarely, and the philosophical and psychological reality of atheism itself. In contrast, Christianity not only provides a basis for the idea that truth is of intrinsic value, but provides resources to enable the Christian to conform his beliefs and behavior to the truth. I would like to gently suggest that those who value truth-seeking and realism should consider whether atheism can justify or support either of these ideals.