I would like to say a little about the traditions of man. Over the centuries, traditions have developed in different cultures, and because many (or most) of these traditions have their origin in man, they do not honor God and actually take away from the real meaning of the wedding.
May I encourage a couple seeking to honor God in their union to look at these traditions squarely and lay aside anything that brings the ceremony down to a natural, earthly level that does not honor God? Whatever is inconsistent with the nature of God and takes away from the example of Christ and His bride should be discarded. Is that too hard? Don't we want to know the real blessing of God in such a time? Do we want to give forth a clear testimony of the nature and character of God? I believe we do, so let us be guided by the Holy Spirit and not by the traditions of this world.
As I have already said, the traditions I am speaking about vary from culture to culture, so I will not be specific. Many take the opportunity to be foolish, reveal the flesh, make fun of intimate things, and embarrass the bride and groom. Men seem to think that on this day they have liberty to bring intimate things into the open and joke about them. Does this admonition of Paul apply? "Let no corrupt word proceed out of your mouth, but what is good for necessary edification, that it may impart grace to the hearers. And do not grieve the Holy Spirit of God, by whom you were sealed for the day of redemption." (Ephesians 4:29-30)
My appeal is that in the entire occasion--before, during, and after the wedding--all things be done to the glory of God. This includes dress, conduct, speech, and music. Surely it is a joyous occasion, but we can still glorify God in all things. Whatever our part, may the Lord lead us. Remember that we do not need to please man. We only need to please God. It is God with whom we all have to do.
Not everybody at a wedding will know the Lord. It is usually a mixed multitude of believers, family, and unbelievers. It is a wonderful opportunity to declare the riches and love of God by what is said and done. Because of the symbolic parallels between the marriage relationship and our relationship to the Lord, there is a wealth of opportunity to proclaim the Lord in a proper way. If the gospel is proclaimed in word and deed, the Holy Spirit can apply it to hungry hearts and draw men to Jesus.
I am not necessarily speaking about preaching, although there may be a place for that. I am primarily talking about the conduct of the occasion and what is included or excluded. If we try to mix worldly tradition with the things of God, it will take away from the power of the witness. There are many passages of scripture related to weddings that God can use to help us in our thinking. Matthew 25:1-13, Matthew 22:1-14, and John 3:27-30 are just a few. Let the Lord lead us in these things.