Here is an exercise that I would wager would not only be fun but could generate some good material for sermons at the same time.
Take a small notebook or even a set of 3 x 5 cards with you for a week. Now keep alert to what is happening around you. Every time you can associate a Christian doctrine with some situation that you either observe or participate in, make note of it. The challenge is to see how many doctrines of our faith you can apply to the life around you. During this first week, don’t even try to be serious. Just make the association of doctrine to situation no matter how far fetched.
You may read in the papers about a congressman who has sent nude pictures of himself to some admirer. What doctrine would you associate with that act? Is it self-worship or idolatry? How does his anthropology or understanding of human nature contradict the Christian understanding of human nature? In what way is he denying the theological understanding of what it means to love one’s neighbor? Maybe it is just the theological understanding of the sin of lust. Go ahead and play with it. Now consider what theological doctrine might apply to the short fall in your church budget. Or perhaps you can consider the Christian doctrine of marriage as you engage in counseling one of your parishioners.
Two things are going to begin to happen for you. First, you are going to alert your awareness to the many ways that Christian doctrine speaks to the world in which you live. Second, as you begin to sensitize yourself to this relationship, you are going to begin to collect some very practical illustrations that you can utilize in your sermon preparation.
