Like the fig tree in leaf that Jesus walks up to on His way into Jerusalem, Israel had all the external signs of life, yet no fruit. So He declares that it will never bear fruit again in a pronouncement of judgment. He then tells His disciples that if they had faith and did not doubt, not only would they do the same in declaring fruitless external religion dead, but they would also say to this mountain of Jerusalem below that had yoked itself to worldly empire and been gutted of spiritual life to be cast into the sea. No matter how many external signs of ceremony, liturgy, and ritual a people have, without fruit it is all truly worthless.