Chapter 12 begins with a warning against the "yeast of the Scribes and the Pharisees." Which is to say be aware of their hypocrisy. This is followed by a weaving of parables and teaching that balances faithful living (and its difficulty) and examples of hypocrisy.
4-12 -- make the fearless confession remembering that God values us and cares for us. The great fear of all fears would be to find oneself in the presence of Christ on the last day and not be known. Don't worry about what the confession is going to be. . . trust God in this and all situations.
13-21 is the parable of the rich fool. It is a grave mistake to believe that all that we have or have acquired is somehow ours. Biblical stewardship teaches us that everything belongs to God (all that I have all that I am all that I dream of being is a gift from God) we are merely managers of these resources. The rich fool has forgotten that God has not blessed him for his own ease and comfort but that he might use those resources faithfully for himself, his family and for others.
22-34 is paralleled in the Sermon on the Mount (Matthew 6). We are told not to worry. God provides. Do not worry about food, clothing or our very lives. God knows what we need. It is God's pleasure to give us the kingdom (32). The key verse in this passage is the last one. "For where your treasure is there you heart will be also (34)." Jesus says we do not value what we love we love what we value -- our treasure owns our heart. Put another way whatever has the highest claim, whatever we give the greatest value in our lives is essentially god for us. What has first claim rules our lives. Where our treasure is, there our heart will be.
Understanding that life is not about food and clothing but about our relationship with God and one another we come to verses 35-48 which are two parables about faithfulness and staying awake and alert. If we are to be faithful we need to pay attention and watch for the signs of Jesus arrival -- in our day to day lives and his ultimate return.
49-53 -- Jesus causes division. I do not believe it is Jesus plan to divide but his very presence does divide. Before I became a Christian I had two good friends. We were dope smoking buddies. That is what we did. we went out a night to score some dope, to smoke it together, and, to make a little music when we could. I thought we were the very best of friends. When I became a Christian these two friends disowned me after one invitation from me to them to at least give Jesus a look. It was clear that what bound us together was not our friendship but our activity together. We were quickly divided. This same scenario plays out in clubs, homes, schools as one or more choose a different way of living. This scenario is played out in churches as people choose to stop playing pious games and religious activity and actually enter into a relationship with Jesus.