Hich is not a purpose of church mosaics?

The correct answer (since there are not any choices listed) should be something about dealing with nature. The churches did not agree with the thought of nature being what was important biblicaly or religiously. Nature  would symbolize science rather than religion.  Many placed mosaics in churches by the means of windows. This helped give the mosaics a radiance, such as that of God and his angels would display. 

Where’s the image at?