More and more adults identify as atheist, agnostic, or “nothing in particular.”

Despite the beliefs of US founding fathers, Christianity has been at the forefront of the country’s social and political ideology. In the past 50 years, religious matters have become even more prevalent in American public discourse, spilling into virtually every aspect of society.

But that may soon change.

In the early 1990s, 90% of US adults self-identified as Christians. In 2007, the figure was 78%. Now, according to a Pew report, the number is down to 64%. Meanwhile, the percentage of adults who don’t declare any religious affiliation has surged to 29%. All other religions, including Judaism, Islam, Hinduism and Buddhism, account for approximately 6%.

Starting from this, Pew teamed up with GSS to estimate how the number will likely change in the future, taking into account relevant factors like migration and demographic changes.

The researchers concluded that four potential scenarios are likely:

• one in which there’s a stable rate of people moving in and out of Christianity;
• one in which Christians are increasingly leaving their religion;
• one in which some Christians are leaving their religion, but no more than 50%;
• one in which no one changes their religion.

In all four scenarios, the number of religiously unaffiliated people was estimated to equal or exceed the number of Christians by 2070.

“Depending on the future of religious switching, people who identify as atheist, agnostic or ‘nothing in particular’ could become America’s largest (non)religious group within our lifetime,” Pew researcher Stephanie Kramer tweeted.

The different scenarios showed different timeframes in which Christianity would lose its dominance in the country. There’s only one scenario in which the religiously unaffiliated wouldn’t outnumber the Christians, the one in which no one changes their religion (and all the changes are from new births) — but even then, the shift would continue, albeit at a slower pace. This is an unlikely scenario, the Pew researchers explained. Meanwhile, at the opposite end of the projection, one scenario had more religiously unaffiliated people than Christians by 2045.

While the exact timeline remains somewhat unclear, it’s clear that the US is undergoing a significant change in religiousness, a change that is likely to reverberate into political and social aspects. Religious arguments are often brought in social aspects like abortion or education, but if this change is any indication, these arguments could gradually lose strength, giving way to more humanistic policies.

The trend isn’t restricted to the US. Many developed nations are experiencing a decrease in religiousness. If anything, the US is an outlier in how prevalent religion still is. But if this study is any indication, that will soon change.