Did my friend say that? Is that a real video of President Trump? New technology allows just about anyone to create footage of people appearing to say things they’ve never said. Bogus videos—called deepfakes—are the latest weapon in the disinformation wars.

Deepfakes are so named because they utilize “deep learning,” a form of artificial intelligence. They’re made by feeding images and audio of a person into a computer. A program learns how to mimic that individual’s facial expressions, mannerisms, and voice. The computer then produces footage of a person “saying” whatever the programmer wants. Deepfake technology produces footage so real-looking it’s hard to spot phonies.

Fake video that speaks lies. Sounds like something God hates: “a false witness who breathes out lies.” (Proverbs 6:16-19) Deepfakes will probably fool many people. And as the technology develops, people will need “constant practice to distinguish good from evil.” (Hebrews 5:14)

Digital forensics expert Hany Farid says, “We have entered a new world where it is going to be difficult to know how to believe what we see.”

The U.S. government is developing technologies to detect fake images and videos. But identifying deepfakes takes complex analysis.

U.S. lawmakers and intelligence officials worry deepfakes could threaten national security or hamper elections. A politician could produce a phony recording of an opponent telling a lie. Or a bogus video of a soldier committing treason. Imagine fake footage of a North Korean or Iranian official informing the world of a looming attack.

The reverse is also a concern: People could become so wary of deepfakes that they dismiss genuine footage as fake—like a national disaster where no one sends aid because they distrust the footage they see. Others might say something for real—and then claim they didn’t, blaming the evidence on deepfake tech.

So far, none of that has happened. But experts claim it’s not a question of if, but when.

Deepfake technology still has a few glitches. For instance, blinking eyes in fake videos can look unnatural. But the technology is improving. International security expert Andrew Grotto says, “Within a year or two, it’s going to be really hard for a person to distinguish between a real video and a fake.”

Bible wisdom says, “Every charge must be established by the evidence of two or three witnesses.” (2 Corinthians 13:1) That advice has always been sound—now more than ever, as separating fact from fiction gets a lot harder.