The millennials are now able to see and hear atheists online who are presenting logical reasons for why religion is irrational and a dangerous concept that needs to be discarded for atheism.

It's because of multiple reasons. The development of science has brought about the eradication of myths. Education is also responsible I think; but it is the sheer connectivity of people all around the world due to Internet and other similar technologies that has a greater impact on people. They can now know about other cultures and their beliefs like never before. This has brought in them the question of the validity of their own beliefs. Internet has also made it possible to access unlimited information, educating more people on these stuffs. Here atheist advocates also play a role.

The movement is not new. In 1972m Jean Jacques Revel wrote a book entitled, WITHOUT MARX OR JESUS. Revel, a French journalist, described how (particularly in Europe) people were becoming intellectually, emotionally, and culturally mature enough to realize that they did not need either political or religious total system ideologies (ideologies which purport to include, explain and control everthing0 to find meaning, purpose and identity in their lives. That realization now dominates in much of Europe. It has been slowly gaining strength here in the US for well over 50 years.

The massive amount of scientific information available online that disproves a lot of religious claims.

Might it be because they see and are confounded with their parents genuflecting, holyrolling and drinking the imaginary blood of some hell preventing savior who committed suicide to make things easier for to manage life.

Because religion never made any sense or had any factual basis. As we learn more and can explain more and more, there is much less need to rely on supernatural explanations for the unknown.

the western youth are better educated and less indoctrinated. The hubble telescope plus the particle accelerator have done wonders for rationality. Even a muppet knows nothing can control 7 trillion galxies

I think it's because millennials are actually able to think for themselves especially with the aid of unlimited information at their fingertips 24/7.

Less worry ...less weight you have to carry in your head... It's taking the parts that are not needed and running it in a more stream line manner. We are driven to do things faster and the quickest way is to knock out the stuff that dosent add up.

I have to agree that access to vast amounts of information practically instantly has made a huge difference, They are now not so gullible as previous generations.

Common sense along with access to information and opinions on the internet. Religion has had an unbelievable run and they have been able to most of the people all of the time, if they didn't they just killed them, but now the momentum is with the secular and the atheists. Religion will never die, but it's lies and power will never be the same again.

Easier access to information, a lot more of those 'I wonder why...' questions are a mere google search away.

Because of abuse and religious harassment is much like sexual harassment. People who weren't abused by religious figures taking advantage of power are just as put off by obvious charlatans bilking people for money. I'm stumbling upon a greater scandal of how people have used religion to sexually abuse and enslave since the 1970's.

I find that to be a positive trend but I don't believe it's happening for millennials in general as much as it is millennials in the US. Which brings us to the question of why so many people in our country believe at all while non-theism has taken strong root in the comparable countries of Canada and the UK.

Less exposure to church I think...