You will never have a perfect message, but prayerfully do what you can.
It is super helpful to evaluate your sermon after you preach it. But it is also vital to evaluate it before you preach.
Here is a partial checklist that may be helpful:
1. Think about the biblical text
Have you answered the questions that the text raises as your listeners read it (for maybe the first time)? Does your message still have the authority of the biblical text or has your message preparation led to any drifting from the meaning of the passage? Is your main idea the main idea of the passage? And is your main idea going to engage your listeners?
2. Think about your listeners
Is your message going to communicate the relevance of the passage to your specific listeners? Is your support material going to connect with different demographics in the congregation (or do you only use sporting illustrations throughout?)
Does your message only communicate to the in-crowd in Church language, or will it communicate to any guests present? Are there any points of connection between message and congregation that require extra sensitivity? It is better to think that through before, rather than trying to fix damage later.
3. Think about the communicator
How are you doing spiritually? And relationally? And physically? Is there anything you need to put right or address in the time between now and when you have to preach?
Do you need to ask someone for help with a pre-preaching responsibility so that you can be in the best place personally to preach? (Don’t be afraid to be vulnerable and admit to a trusted friend if that is the case.)
4. Think about the Spirit of God
Apart from God working through this sermon, it will achieve nothing. Have you prepared prayerfully? Do you need to seek forgiveness for self-reliance or distraction and bring the congregation and the message to the Throne of Grace now?
Remember, you will never have a perfect message, but prayerfully do what you can. In fact, prayerfully evaluate the message and you will probably have a sense of where to put your energies in the time you have left!