To prepare a sermon, first ask God for help in understanding the Bible passages you are reading. Look up the passage in different versions of the Bible to check any additional word meanings. Make notes about the passage and use them to form an outline for the sermon, including references to the scripture. When the outline is finished, practice the sermon, even if it is just in front of the mirror. Constructive criticism from acquaintances can be useful.
The sermon's outline should be a guide, rather than a long passage that the pastor reads out. Try to read Bible passages dynamically, so you and the congregation can both be inspired. At the sermon's start, clearly state the book and verse that are under discussion, so that people can find it in their own Bibles and read along.
Introduce the topic by explaining how it is relevant; perhaps the sermon relates to recent world events, for example. Develop the message using scripture, rhetorical questions and real-life examples. Remember to keep the sermon focused on God. For example, if the sermon is about forgiveness, use what God says about forgiveness rather than your own thoughts.
It is a good idea to have a maximum of three main points in the sermon, so that people can remember as much as possible. Save the main point for the end, as this remains freshest in people's minds. Conclude the sermon with a call to action.