I would divide "chapter 11" was differently. (Remember, there were no chapters and verses in the original document.) 11:27-33 belongs with chapter 12, where there is a long section detailing the controversy over Jesus' identity and authority in Jerusalem among the different factions of leadership. It is no surprise that the section ends with a contrast between the scribes who devour widows' houses for themselves and a widow who gives everything to support God's house. Chapter 13 speaks about the coming judgment.
But in chapter 11, there is an introduction followed by two scenes of Jesus' symbolic judgment against Jerusalem. In between the scenes of judgment, Jesus clears the temple. What is happening here?
Jesus enters Jerusalem as a king. This is in accordance with scripture. The people recognize him as King, as the one who comes in the name of the Lord, and they praise and worship him. Jesus then goes into the temple for the first time. (Note that in Mark, Jesus enters the temple here twice.) He looks around and sees nothing remiss, so they leave the city.
The next day, on his way back to the city (he is outside the city) Jesus sees a fig tree in leaf and he is hungry, so he goes to it but does not find figs. Mark tells us that it was not the season for figs. But Jesus curses the tree, and declares that no one will eat fruit from it ever again. How is it the fig tree's fault? The fact that the tree was in leaf indicated something about a first crop, but it was barren.
The fig tree gave the appearance of being in season but it was barren. This corresponds to Jerusalem.
The leaves on the tree were like the triumphal entry and the generic appearance of the temple. It looked good. But there should have been fruit, and there was none. This failure to bear fruit is seen when Jesus goes back to the temple. Now he seems improper and unethical things happening in the temple; it is not the "house of prayer" that scripture foretold it should be. The indication of a crop of righteousness was there (his welcoming by the people and the benign state of the temple the previous day), but the fruit was not there. In fact, the religious leaders themselves were barren. Where they should have borne fruit, they had borne barrenness.
Later, when the disciples see the barren fig tree, they remark about it. And Jesus teaches them that it is about faith. If you truly see Jesus, you will respond by faith. If you have the leaves of faith, you should also have the fruit of faith. The religious leaders, and Jerusalem didn't. We will see this play out in chapter 12 and in the pronouncement of judgment in chapter 13. But for now, Jesus is holding his band of disciples together with the teaching about faith and discipleship.
Do you believe? If so, are you forgiving? Jesus leaves that as a mark of what true belief and faith is.