In the morning, as they went along, they saw the fig tree withered from the roots. Peter remembered and said to Jesus, "Rabbi, look! The fig tree you cursed has withered!" "Have faith in God," Jesus answered. "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. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours. And when you stand praying, if you hold anything against anyone, forgive him, so that your Father in heaven may forgive you your sins. But if you do not forgive neither will your father who is in heaven forgive your sins."
Jesus' judgment on the fig-tree had immediate effect. Were Peter and the other disciples tempted to think of this as some kind of special 'Son of Man magic'? But if they did, Jesus didn't talk about faith as if it were a form of magic.
He told His disciples that just as He had judged the fig-tree for not bearing fruit, so also He had to reckon with His Father in Heaven when He stood before Him in the temple to pray. There, in God's temple, He prayed. He told His disciples how He prayed. In the temple, He had been standing before the Almighty and from His heart forgave all who had sinned against Him. He forgave the chief priests who were supposed to pray for the people, but who had allowed the temple to be turned into a religious market. Jesus also prayed for the scribes and the money-changers. From His heart He forgave them. He forgave those who, having given up their prophetic religion, tried to safeguard themselves under the shadow of the Roman Eagle. He forgave those shepherds of the Children of Israel who would sacrifice the Son of Man by handing the Lamb of God over to Pilate for a bloody crucifixion.
Now we can understand Jesus' talk about mountains being thrown into the sea. Faith can move mountains. But how can anyone forgive when they are praying to our Heavenly Father if it is not through a miracle of God's grace? Forgiving those with whom we are angry when we are praying is the best way to deal with our anger. Peter came to understand this.
Humble yourselves therefore under the mighty hand of God, that in due time he may exalt you; cast all your anxieties upon him, for he cares for you. Be sober, be watchful …. (1 Peter 5:6-8)
I think we are to infer from this that after He threw out those sellers and buyers, all those animals and birds, Jesus went into that part of the temple where they could pray and before He put His prayers before His Heavenly Father, He forgave them. You could say that He was getting into practise, because on the cross, you remember, He prayed: Father forgive them! They don't know what they are doing! He may not have had any sins of His own that needed to be forgiven. But He told His disciples that the Son of Man, the lamb of God who had come to take away the sins of the world, still needed to have His prayers heard when He stood there in front of the Almighty. And that is the important point. Think of it like this: if, when Jesus prayed, He wasn't forgiving those who had sinned against Him, then He was the hypocrite! He had taught His disciples to forgive, and if He hadn't forgiven those who sinned against him then, on His own terms, He was no longer qualified to stand before God on our behalf!
So that is how Jesus taught His disciples about the withering of the fig-tree. It meant: live by faith in God and forgive. The point is that from His teaching it is easier for a real mountain to be thrown into the sea, or a fig-tree to wither due to a curse, than for a mountain of hate to be removed from our hearts. How do we remove a mountain of hate? We can't. But God works miracles.
It is not our anger that can do it, even if we should get angry at the hate some may show to us. It is not by cursing figless fig-trees although when our lives become fruitless then we need pruning. Jesus says forgive. Forgiveness is a matter of faith. We forgive by faith, just as God has kept His Promises and forgiven us. Jesus helped His disciples see and understand His anger. The fig-tree should have already been cut down because it had no fruit and was just taking up the soil. Its time was up. Its purpose was in its fruit - no fruit, cut it down.
The rule is that when we stand before God to pray, we forgive. Forgive us our sins as we forgive those who have sinned against us. When we stand before God we cannot hide the judgments we are making in our hearts. It is not our task to judge people, even if there is a judgment we have to make about fruitless developments in life. So we forgive. If we are angry and furious, we pray to God. By prayer we seek God's deliverance but first we must forgive.
By cursing the fig-tree Jesus taught His disciples about the meaning of His anger in the temple. It was an event of faith and prayer. If we are not forgiving we miss out on the freedom God wants us to have in uttering our prayers. Consigning a fig-tree to the flames is within our legitimate human responsibility; cursing others however is to deny that we also need forgiveness just like those who have sinned against us.