Jesus explains that very clear in the next verse about having enough faith you can accomplish anything you want.
Future prophecies are supposed to be disguised because man will try to alter them if he knew what they were. But false teachings aren't about future prophecies. They are always trying to change verses like Leviticus 18:22 into the
opposite like "God loves homosexuality"
Or changing the word "eternal" to mean
"not eternal" that universalists try to do...you know redefining words like "is."