Four movements, eight minutes. This is the homily inside the service, not the officiant's script for the vows and the declaration.
Something only you know
2 min[specific to this couple - this is the whole value of having a pastor do it]
[one true specific thing you have seen these two do for each other - small, concrete, not a virtue list]
The room is full of people who love them and have never seen them at their least impressive. You probably have. That is what you bring.
The text, and the 1 Corinthians problem
3 min[if you read it, say what it actually is]
If the couple has asked for 1 Corinthians 13, read it, and then say the thing nobody says: Paul was not writing about marriage. He was writing to a church that was falling apart over who had the better spiritual gifts, and the love passage is a rebuke.
That makes it better, not worse. It means love is not described here as a feeling two people have but as a practice a group of people owe each other when they would rather not.
[or use Ruth 1:16-17, or Ecclesiastes 4:9-12, both of which are about loyalty rather than romance]
The turn: a promise, not a feeling
3 min[this is the claim and it is the only one you need]
In a few minutes these two are going to make promises in the future tense about things they cannot possibly foresee. Sickness they do not know is coming. Poverty they have not budgeted for.
That is the striking thing about a wedding. Not the feeling in the room, which is real and will fade by Tuesday, but two people binding themselves to a person who will change, in conditions they cannot see, in front of witnesses whose job is to remember.
[your material, 250 words]
The charge to the room
1 min[give the guests a job - it is the most underused minute in any wedding]
To everyone else: you are not decoration. You are witnesses, which is a role with a duty attached. At some point in the next forty years one of these two will ring one of you at an hour that is not convenient. Answer.
[hand into the vows]