More young people are losing faith in God, according to a recent Pew survey.

About 68 percent of Millennials say they never doubt the existence of God, a decline of 15 points since 2007, while the number of older Americans with a firm belief in God remains stable. Millennials are defined by Pew as those young Americans born in 1981 or later.

Other studies appear to confirm this trend - more than half of non-religious Millennials have abandoned their childhood faith, according to a recent study by the Public Religion Research Institute and Georgetown’s Berkley Center for Religion, Peace & World Affairs.

Catholicism and other forms of Christianity aren't the only congregations losing ground. The study says that “one-quarter (25 percent) of Millennials identify as religiously unaffiliated.” Not only that, since only 11 percent of Millennials were raised without faith, more than half of unaffiliated Millennials left their childhood faith.

The gap also applies to conservative ideas - back in 2007, almost half (46%) of Millennials agreed that books with dangerous ideas should not be permitted in school libraries but that number has dropped 18 points (to 28%) in the Pew survey. The views of older Americans on that issue have not changed.