Jesus had said to the crowds "You can look at a cloud and know when it's going to rain, but you seem to be missing more important signals (my rewording of Luke 12:54-56).
He then brought up some recent misfortunes. "They weren't repayments for misdeeds, but sin does have consequences."
Not all misfortunes indicate that the sufferer deserved what happened. Bad things do happen to good people. But, don't let that lull you into a misunderstanding. Repentance is necessary.
Jesus then told them the parable of the fig tree. The fig tree owner was ready to cut down the fig tree that hadn't produced any figs for three years, but his gardener argued for one more chance, "Let me dig around it and fertilize it, and then if it produces fruit, well and good. But, if it doesn't show any change after this other chance, then cut it down.
Unlike the Galileans sacrificed by Pilate or the eighteen who were killed by the collapse of the tower of Siloam, we may well deserve punishment. Let us look at our lives for the last three years and measure how much fruit we have produced. What would the owner of the orchard have to say? Would the resources we consume be more profitably put to use by other trees?
Don't confuse a delay in judgment with approval of what we're doing.
Let us not be lulled by all the mercy we have received. It's time to repent.