From chapter 6 of How to Lead Evensong by Gilly Myers, published by Grove Books 2005.
If there is no one to preach, there are still things that can be done during the ‘sermon’ slot. Here are a few simple examples:
Some bible commentaries are very accessible to ordinary people and are far from the academic tomes, full of Greek words and long sentences that clergy had to read at theological college! Having a storytelling style, they would work well if they were read out loud in a reflective manner. Bishop Tom Wright’s series Paul for Everyone and William Barclay’s Daily Study Bible are examples of this.
Ask a local minister who is preaching on the same Bible readings that day if their sermon could be delivered in your church too. Then find someone who would be able and willing to read it well.
There are books of sermons and homilies available, but their quality is variable. Check well in advance that they are suitable.
There are some websites that provide ready-made sermons, but be careful – they might be dreadful!
If you, or another member of the congregation, are used to leading a Bible study group, and the congregation would cope with this approach, you could consider putting together some questions to stimulate a short discussion about one of the readings.
What can we do if we are absolutely stuck?
It may be that omitting the sermon is unavoidable. If you have been asked to lead the service, and not to preach, then it is not your responsibility to produce a sermon. If this is a long-term solution, then there needs to be some discussion in the church as to how the congregation is going to crack open the Scriptures on a regular basis.