In the life of the church, weddings are a welcomed oddity, though few would describe them as such.  They are a hodgepodge of contractual language, religious forms, and moral admonition, plus a little anxiety and food.  Compared to others services, a funeral, for instance, the wedding service is a mix of competing elements.
      The first reason for the wedding jumble is that it is at least as much as civil service as a religious one.  For this reason alone, some ministers in a number of denominations recommend that all marrying persons have a civil service, while those with a particular religious commitment then get their marriage blessed in church.  Given the emotional expectations by many of the wedding rite, this is as likely as justices of the peace welcoming all those extra services.
      Nonetheless, the core of the wedding service is the pledge and covenant summarized in the words: "I thee wed."  Even the ring -- given an inflated meaning in the "eternity of the circle" and the "purity of gold" -- is inessential.  A wedding service could be as simple as that, but the only time I have heard of that was when serial killer Ted Bundy contracted marriage during his trial: not a happy precedent.
      And yet to refer to "contracting marriage," though accurate, is incomplete.  In theological terms, marriage is a particular for of covenant between two persons.  There are many kinds of covenant.  There are covenants between God and humanity, whether that be all of humanity, a particular nation, a particular congregation (hence, the warrant for congregational polity), or an individual.  The terms of the covenant are worship and obedience to God; God returns mercy and steadfast love.  There is a covenant between God and the rest of the natural world: "Praise the LORD from the earth, you sea monsters and all deeps, fire and hail, snow and frost, stormy wind fulfilling his command!" (Psalm 148: 7, 8, NRSV)  There is a covenant of stewardship between humanity and the natural world.  And there are covenants between human beings.
      We find human covenants in the gathering of congregations, the calling of their ministers, the just order of government, and in marriage, among others.  The terms vary, but trust, loyalty, and mutual care are constant.  Because we associate covenants with one another (often under the fuzzy caption of "character") President Clinton's recent admission of wrongdoing with Monica Lewinsky, will be associated with his covenant with the nation, as president.  He must repair his relationship with Mrs. Clinton and the American people alike.
      The wedding service prepares the candidates for marriage for these responsibilities, at least in a ritualized way.  Indeed, much of the first half of the service is dedicate to it.  The whole "dearly beloved. . . ." part (pulled from the old Episcopal service and popular in many denominations) is an exhortation on the nature of marriage.  The vows ("to have and to hold") establish the conditions of the covenant, hence the legitimate fight over the obedience clause sometimes found in the woman's vows.  Prayers often recall God's covenant with humanity and the church, as a mirror for the covenant.
      Biblical readings are a hazard in the wedding service.  Despite the options, the old saw -- 1 Corinthians 13 -- is used more than others.  Nobody ever uses the most appropriate passage about the household:

Do not think that I have come [says Jesus] to bring peace to the earth; I have not come to bring peace, but a sword.  For I have come to set a man against his father, and a daughter against her mother, and a daughter- in-law against her mother-in-law; and one's foes will be members of one's own household.  Whoever loves father or mother more than me is not worthy of me; and whoever loves son or daughter more than me is not worthy of me; and whoever does not take up the cross and follow me is not worthy of me.  Those who find their life will lose it, and those who lose their life for my sake will find it. (Matthew 10: 34-39, NRSV)

      Exodus 22:16-17 is no better. (Look it up.)  1 Corinthians does look better by comparison, but so do a number of passages from the Song of Solomon (like 2:16-3:5) or the Prophets, if you want something less steamy.  Jeremiah 31:31- 34 and Isaiah 55 leap to mind: these are images of God's covenant with humanity fulfilled.
      The first half of the service is solemn; the second half is joyous, but usually briefer to avoid an anti-climax. Here comes the prayers of thanksgiving and blessings upon the couple and others, which is usually the most explicit place for theology. Neither Unitarianism nor Universalism have developed marriage theology, but our close kin in the Free churches do.  Marriage provides company, help, and happiness in the context of love and nurture.  Sexual love is one expression of the relationship, and is a positive virtue apart from reproduction, whether or not that is desired or possible.  Marriage is more than a hedge against fornication!
      The service, if composed carefully, does not need the tatty material embellishments hawked by florists and others.  A jungle of flowers, clothing (especially, "the dress") that would be ridiculous elsewhere, and a tangle of candles are unfortunate distractions.  Among these, none is worse than the mock tradition of the "unity candle": it betrays the idea of covenant (and common sense) when two candles become one -- and the two individuals are extinguished!  A Broadway production number of a wedding is fair game for ridicule.  Hence comes the whispered want, "I like a simple wedding."  Simplicity allows the love, and commitment, and hope to glow in their own light.