UPDATE (from Xavarian Missionaries ): 

Oscar A. Romero, Archbishop of San Salvador, in El Salvador, was assassinated on March 24, 1980, while celebrating Mass in a small chapel in a cancer hospital where he lived. He had always been close to his people, preached a prophetic gospel, denouncing the injustice in his country and supporting the development of popular and mass organizations. He became the voice of the Salvadoran people when all other channels of expression had been crushed by the repression.

The following prayer was composed by Bishop Ken Untener of Saginaw, drafted for a homily by Card. John Dearden in Nov. 1979 for a celebration of departed priests.  As a reflection on the anniversary of the martyrdom of Bishop Romero, Bishop Untener included in a reflection book a passage titled "The mystery of the Romero Prayer." The mystery is that the words of the prayer are attributed to Oscar Romero, but they were never spoken by him.

It helps now and then to step back and take a long view.
The Kingdom is not only beyond our efforts,
it is beyond our vision.

We accomplish in our lifetime only a fraction
of the magnificent enterprise that is God's work.
Nothing we do is complete, which is another way of
saying that the kingdom always lies beyond us.

This is what we are about. We plant the seeds that one
day will grow. We water the seeds already planted
knowing that they hold future promise.
We lay foundations that will need further development.
We provide yeast that produces effects
far beyond our capabilities.

We cannot do everything, and there is a sense of
liberation in realizing this.
This enables us to do something, and to do it very well.
It may be incomplete, but it is a beginning,
a step along the way, an opportunity for the Lord's
grace to enter and do the rest.
We may never see the end results, but that is the
difference between the master builder and the worker.

We are workers, not master builders, ministers, not
messiahs. We are prophets of a future not our own.

-- Archbishop Oscar Romero (martyred on March 24th 1980)