It is generally accepted that reducing conditions are essential to synthesize the ingredients of life. However, geological records dating back close to - but not quite - the Hadean eon suggest that the Earth's atmosphere was oxidizing. Then how was the primordial soup prepared on early Earth? Combining insights from geology, chemistry, and astronomy allows us to see the bigger picture in an interdisciplinary approach. We are free of any bias towards one of the many proposed mechanisms that might have contributed to the reduction of the Hadean atmosphere. To address this, we extend an established photochemical model of the Earth's atmosphere with several different proposed sources of reducing gases. We systematically study their impacts as well as their interplay. Coupling this with a wet-dry cycling model of small bodies of water on the first land masses allows us to predict the abundance of life's building blocks on our planet.