This is a great example of Jesus teaching/showing His disciples how Israel had failed to produce good fruit-look at the horrible things going on in the Temple.
Mark 11
15On reaching Jerusalem, Jesus entered the temple area and began driving out those who were buying and selling there. He overturned the tables of the money changers and the benches of those selling doves, 16and would not allow anyone to carry merchandise through the temple courts. 17And as he taught them, he said, "Is it not written:
" 'My house will be called
a house of prayer for all nations'? But you have made it 'a den of robbers.'"
18The chief priests and the teachers of the law heard this and began looking for a way to kill him, for they feared him, because the whole crowd was amazed at his teaching.
19When evening came, they went out of the city.
20In the morning, as they went along, they saw the fig tree withered from the roots. 21Peter remembered and said to Jesus, "Rabbi, look! The fig tree you cursed has withered!"
22"Have faith in God," Jesus answered. 23"I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. 24Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours. 25And when you stand praying, if you hold anything against anyone, forgive him, so that your Father in heaven may forgive you your sins."