Just like us, Jesus’ disciples are disturbed by events in which seemingly innocent people die in unfortunate ways. Jesus uses this to teach that everyone will eventually die, and it is best to be in a good relationship with God. Luke then begins to tell of the ways Jesus was warning the Jews that they do not have exclusive access to God. The fig tree was not safe just because it was a fig tree - it needed to bear fruit. People are not safe just because they come from a good religious background - they need to have a relationship with Jesus. Jesus is going to call people from far and wide regardless of their history.
It’s good to know we have access to God regardless of our background. It’s what enables any of us to trust Christ and receive all the benefits of a relationship with God. But there is a warning here not to take our relationship with God for granted. We have it based on our trust in Jesus, not because it is owed to us.