Overheard this question recently:
If science were to disappear, the world as we know it would collapse into another Dark Age. But if theology was no more? What would we lose?
First off, the question is a bit of a strawman, because it is comparing the results of scientific knowledge (our current technologies and understanding of the universe) with the vague notion of ‘theology’ which of course isn’t a single thing, but instead disparate ideas which people may or may not act on. We don’t know what effects current theological ideas might have in the future, just as we don’t know what impact current scientific ideas might have in the future . There are after all many scientific theories in existence today which would have no discernible impact if the knowledge of them were gone; string theory comes to mind for example. But we do know what effects past theological ideas have had.
So a fair comparison would be if we compared the impact of scientific knowledge over time to the impact of Christian theological knowledge over time.
We know for example that the impact of certain theologies produced most classical Western works of literature, music, and art. It influenced great thinkers and scientists like Newton, Pascal, and Bacon, who were theologians as well as scientists and thinkers.
As I have pointed out elsewhere, it influenced the creation of unified languages, which in turn inspired the character of nations, as well as political and social movements like the Reformation, a critical turning point in Western culture and political thought. It influenced the establishment of many of the greatest universities like Yale and Harvard, in addition to essential social organizations like hospitals, orphanages, the Red Cross and the Salvation Army. It inspired important concepts like human equality and the endowment of inalienable rights, and furthered adoption of the same through groups like the Abolitionists.
It encouraged the Puritans to seek and establish new lands. It positively influences and transforms countries today, a fact recognized by even its detractors.
Those are just a few critical aspects of our lives we owe to Christian theology. So had it not existed, neither than would our science, nor the culture in which science now operates. Theology is certainly more critical.