"So yes, Biden, the guy who goes to church each and every week is apparently the antichrist ..."

Actually, if you consider the church that Biden goes to every week is Catholic, it all makes more sense, though not in any kind of rational way.

Typical Evangelical Christian eschatology holds that the Catholic Church is the "Whore of Babylon," a prophesied biblical figure that will partner with the Antichrist. Hal Lindsey's "Late Great Planet Earth" popularized this notion as far back as the 1970s and it has gained much currency in Evangelical circles. The notion that the Catholic Church will help bring about the rise of the Antichrist is taken for granted in Evangelical circles. (The Late Great Planet Earth is still required reading in most Bible colleges where Evangelical clergy are trained.)

Evangelicals and Catholic clergy find political common cause when it comes to criminalizing women and doctors for abortion, and of course for legalized queer bashing, but Evangelicals do not like Catholics, even insisting Catholics are not Christians. (I specify the Catholic hierarchy, because lay Catholics in the United States differ wildly in their beliefs from nuns, priests and bishops. The average American lay Catholic is actually more likely than the general public to oppose the sort of transphobia and homophobia the official Church fights for at law.)

The Catholic hierarchy seem willing to overlook for practical purposes that evangelicals hold them in high disdain. Uniting to hate on marginalized people takes precedence, apparently.

But in light of all that, it's not actually strange that an Evangelical Christian would describe Biden as a possible Antichrist. The sort of belief system that supports that is mainstream in American Christianity.