A sermon. Quite a good one really.

Be who God meant you to be and you will set the world on fire."

So said St Catherine of Siena whose festival day this is. Marriage is intended to be a way in which man and woman help each other to become what God meant each one to be, their deepest and truest selves.

Many people are fearful for the future of today’s world but the message of the celebrations in this country and far beyond its shores is the right one – this is a joyful day! It is good that people in every continent are able to share in these celebrations because this is, as every wedding day should be, a day of hope.

In a sense every wedding is a royal wedding with the bride and groom as king and queen of creation, making a new life together so that life can flow through them into the future.

William and Catherine, you have chosen to be married in the sight of a generous God who so loved the world that he gave himself to us in the person of Jesus Christ.

In the Spirit of this generous God, husband and wife are to give themselves to each other.

The spiritual life grows as love finds its centre beyond ourselves. Faithful and committed relationships offer a door into the mystery of spiritual life in which we discover this: the more we give of self, the richer we become in soul; the more we go beyond ourselves in love, the more we become our true selves and our spiritual beauty is more fully revealed. In marriage we are seeking to bring one another into fuller life.

It is of course very hard to wean ourselves away from self-centredness. People can dream of such a thing but that hope should not be fulfilled without a solemn decision that, whatever the difficulties, we are committed to the way of generous love.

You have both made your decision today – “I will” – and by making this new relationship, you have aligned yourselves with what we believe is the way in which life is spiritually evolving, and which will lead to a creative future for the human race.

We stand looking forward to a century which is full of promise and full of peril. Human beings are confronting the question of how to use wisely the power that has been given to us through the discoveries of the last century. We shall not be converted to the promise of the future by more knowledge, but rather by an increase of loving wisdom and reverence, for life, for the earth and for one another.

Marriage should transform, as husband and wife make one another their work of art. It is possible to transform so long as we do not harbour ambitions to reform our partner. There must be no coercion if the Spirit is to flow; each must give the other space and freedom. Chaucer, the London poet, sums it up in a pithy phrase:

"Whan maistrie [mastery] comth, the God of Love anon,
Beteth his wynges, and farewell, he is gon."

As the reality of God has faded from so many lives in the West, there has been a corresponding inflation of expectations that personal relations alone will supply meaning and happiness in life. This is to load our partner with too great a burden. We are all incomplete: we all need the love which is secure, rather than oppressive. We need mutual forgiveness in order to thrive.

As we move towards our partner in love, following the example of Jesus Christ, the Holy Spirit is quickened within us and can increasingly fill our lives with light. This leads on to a family life which offers the best conditions in which the next generation can receive and exchange those gifts which can overcome fear and division and incubate the coming world of the Spirit, whose fruits are love and joy and peace.

I pray that all of us present and the many millions watching this ceremony and sharing in your joy today will do everything in their power to support and uphold you in your new life. I pray that God will bless you in the way of life you have chosen. That way which is expressed in the prayer that you have composed together in preparation for this day:

God our Father, we thank you for our families; for the love that we share and for the joy of our marriage.
In the busyness of each day keep our eyes fixed on what is real and important in life and help us to be generous with our time and love and energy.
Strengthened by our union help us to serve and comfort those who suffer. 
We ask this in the Spirit of Jesus Christ. Amen.

- Richard Chartres, 132rd Bishop of London,
delivered in Westminster Abbey on 29th April 2011