Addressing Non-Christians
I'm not sure of the exact numbers, but probably 1/3 - ½ of the people there will be non-christians. I (the groom) admit that I honestly don't know what it's best for you to say to them. I ask that you think about what will be helpful for them. If any of these very un-thought-out thoughts seem good or useful, then feel free to use them, but it's fine to not use them:
Remember this isn't the only chance these people are likely to come into contact with Christianity/christians (they at least know us for a start). So it might be helpful to think about what you could say that'll make it easier for Christians to share the gospel with them in the future, or which makes them more open to the gospel. E.g. You could criticize the idea that “religion and politics are taboo topics” or “don't talk religion or politics” which, of interest to the left-leaning person fosters ignorance and a lack of understanding between people; which keeps relationships at a more superficial level; and which gets in the way of true tolerance and graciousness because it's based on the premise that you can only get along peacefully and lovingly with people different from you, if you censor your differences.
I feel it can be unhelpful to say a lot of the things which often start with “and if you're not a christian here.....”. Maybe it's better to mostly just speak to everyone as being under God's wrath and needing forgiveness.
Perhaps we (the groom and the bride) are a helpful point of connection with the non-christians there. They are hearing about what is central and most important in our lives, and our greatest hopes, loves and joys and fears (Heb 4:1).
