Almost every week, we receive a prophetic "warning" of one kind or another from someone who claims to have had "a word from God."

Sometimes these warnings are about the Rapture. Other times they're about imminent natural disasters, political happenings, or other prophetically significant events that these folks have allegedly been told (by God) to warn the rest of us about.

In some cases, these emails arrive after the fact (that is, after a predicted event has already happened—like a bridge collapse, tsunami, mudslide, or terrorist attack). The writer of the email claims to have predicted it before it happened. Forgive me, but I'm a skeptic by nature. I'm always left wondering why I didn't get the memo beforehand.

This latest warning is about a great fleet of extraterrestrial spaceships that will arrive on October 14 and "float above major world cities." Someone else had a dream that he says confirms this coming event and suggests that we need the protection of eagles and tortoises.

I'm serious. Eagles and tortoises—one million of each, in fact. This is really what they're saying.

Come on, folks; I can't make this stuff up.

So according to these people, UFOs will be floating over the world's major cities roughly a week from now. They say it's part of an elaborate "deception." Maybe someone fell asleep during an episode of ABC's "V" and subconsciously absorbed this idea by osmosis.

They claim that the whole scenario was outed by "a retired NORAD official." Hmm. I guess the air gets pretty thin up there in those Colorado mountains.

The Internet has proven to be an almost indispensable tool in missions and other areas of Gospel work. One of the downsides of the World Wide Web, however, is that any crackpot in the civilized world with a few bucks a month to spare can set up a website and broadcast his flaky prophetic theories to the world. What's equally unfortunate is that some professing believers possess so little in the way of spiritual perception or discernment. They're ready to jump on the bandwagon for whatever new theory the wind happens to blow across their path. The Apostle Paul says these folks need to grow up:

That we should no longer be children, tossed to and fro and carried about with every wind of doctrine, by the trickery of men, in the cunning craftiness of deceitful plotting (Eph. 4:14).

The NT warns us frequently about this sort of "trickery" by certain people who want us to believe that they speak with divine authority when they are in fact deceivers. The Lord Jesus himself said that there would be a profusion of "false prophets" in the last days—and their deceptions would be so compelling and so convincing, they might "deceive, if possible, even the elect" (Matt. 24:24b).

But wait a minute. The NT also says that there will be a resurgence of supernatural gifts (specifically, prophecy, visions, and dreams) in the last days, particularly during the Tribulation (Acts 2:17-18), and possibly even before.

This means the true and the false will exist side by side—which begs the question: how can we tell a true prophet from a false one?

Fortunately, we don't have to reinvent the wheel here. The people of Israel dealt with this problem thousands of years ago. During the wilderness wanderings, their very survival hung in the balance. If the nation perished in the desert, the messianic prophecies wouldn't be fulfilled. God's plan of redemption might have been derailed (at least, in theory). So it was vital that they hear and obey God. Israel's very survival was on the line—and the devil knew it. So he did something very cunning and clever: he sent false prophets to confuse the people. The situation got so bad, evidently, that the people didn't know to whom they should listen.

Do you remember those "Where's Waldo" books? Our kids loved them. Each page was filled with hundreds or maybe even thousands of tiny, detailed images—and it really made it hard to pick out the real Waldo. This is what the devil tried to do to Israel. He cluttered up the prophetic pipeline with fake messages so the people couldn't pick out the real ones.

God moved swiftly and decisively to remedy this potentially disastrous situation. First, He decreed that prophetic deceivers should be dealt with by means of capital punishment: "But the prophet who presumes to speak a word in My name, which I have not commanded him to speak, or who speaks in the name of other gods, that prophet shall die" (Deut. 18:20).

I know we had a little fun with the UFO thing a moment ago; but now we've come to something that isn't funny. Presuming to speak for God is an extremely serious business. The Lord himself elevates it to a matter of life and death. The Lord says, in essence, "If you mislead My people, you're going to die."

The second thing He did was tell His people how they could differentiate between the true and the false: "When a prophet speaks in the name of the LORD, if the thing does not happen or come to pass, that is the thing which the LORD has not spoken; the prophet has spoken it presumptuously; you shall not be afraid of him" (v. 22).

How much clearer could it be? If someone claims to have a warning from God (whether he says it came through a dream, a vision, or some other form of divine revelation), and the predicted event doesn't come to pass, then that person is a false prophet and we shouldn't listen to him/her (cp. Jer. 29:8-9).

That's what God said, not me. If you disagree, feel free to take it up with Him.

The irony in all of this is that the warning about deception is itself a deception.

Some of us need to grow up and act like adults. There's enough juvenile clutter out there as it is. We don't need any more.