They are asking non-believers to save their souls before it's too late. These messages were not sent from above, but rather from a nonprofit evangelical group called Family Radio. According to the group's website, May 21 is the day of rapture.
"We are commanded by God in Ezekiel 33 to blow the trumpet and that's exactly what's taken place right now," Michael Garcia from Family Radio said.
Because Family Radio is based in Oakland, a group challenging their belief in the day of rapture have posted signs like, "You know it is nonsense." ABC7 spoke to the President of the American Atheist David Silverman via phone.
"This is how religion hurts people, one of the many ways religion hurts people. Our hope is that those who are not suckered in will learn from the people who are," he said.
"Beseech him while the day is still here, while salvation is still possible, because God will close the door on May 21," Garcia said.
The American Atheists are planning regional celebratory meetings on May 21 and 22.