I understand that by 'Atheism' you mean a lack of faith in 'God' and suspicion of the transcendental being.
Atheists are by nature too realistic and practical with a keen scientific outlook.The world is no longer an unpredictable place ..The scientific equipment of Mankind makes it as predictable as possible.
So Atheism and the Atheist..one who knows the outcome with a realistic outlook...and at this point I know not whether I am a theist or Atheist...as it hardly matters..given the conditions of reality if a GOD exists or not...because...as far as you and I both know..
far too many people exist...people who need no GOD.
WE 'MEN' now know the end of our story..It is no longer a secret our GOD keeps from us..As long as we did not know and hoped in earnest that it is a wonderful story with a happy end..we the faithful did believe in GOD and the Goodness of MAN..So it was basically a belief in goodness of MAN that gave us a firm belief in the omnipotent GOD. ..
However now..none is interested to keep the faith .People are disinclined and demotivated by GOD or Religion ..'Atheism' as you said is spreading...and that is because..
People as a whole have degraded in quality , values and output..If we judge human civilization by the standard of it's scientific and technological output then 21st century has achieved a lot ..but in order to achieve this technologically evolved civilization..man had to pay a great price himself...
Mankind as a whole, is of an inferior quality..and can only fulfill specialized set of function..
So .naturally when one knows that one does not qualify to understand or realize GOD.
..one stops believing and gets busy with everything else..mostly material things (except god...and that is logical)..Because we can no longer imagine, identify or aspire to the ideals of virtue and value that God embodies..we do not believe in God..
The future my friend is too bleak too imagine.