I would say that atheism and religious faith are not either or distinctions but gradients?

The only real difference between atheists and Christians is their attitude on how to deal with the unknown...Christians "walk by faith" -- see Heb 11:1-3 -- "Now faith is confidence in what we hope for and urance about what we do not see; By faith we understand that the universe was formed at God’s command, so that what is seen was not made out of what was visible." Atheists, on the other hand, are (obviously) quite uncomfortable with the unknown/unseen.