A new poll from the Pew Research Center shows a decline in the number of Americans who identify themselves as Christians.

The survey showed the percentage of Americans who identify as Christians fell almost 8 percent, from 78.4% to 70.6%.

The survey showed that the decrease is because of millennials leaving the church.  Since 2007,  the number of millennials who say they are unaffiliated with any faith has increased 10 percentage points.  More than one-third of millennials say that they have no faith.

However, the number of those who say they have no faith does not mean there has been an increase in atheism; the poll showed only a ride from 1.5% to 3%.  A Pew researcher noted that many who said they have no faith were just choosing to not identify as religious.

“It’s not as if young people today are being raised in a way completely different from Christianity,” said Greg Smith, Pew’s associate director of religion research and the lead researcher on the new study. “But as adults they are simply dropping that part of their identity.”

Gregory Jones, senior strategist for leadership education at Duke University, cited a different survey that showed 70% of youth pastors have no theological education and said perhaps the problem is that students are not being engaged intellectually by leaders on issues that matter to them. Jones said it leaves the youth bored with church.

“If it is the case that millennials are less ‘atheists’ than they are ‘bored,’ then serious engagements with Christian social innovation, and with deep intellectual reflection (and these two things are connected), would offer promising signs of hope,” Jones said.