During the Medieval and Gothic eras the church was quite wealthy and influential, so it was able to offer a lot of money to a talented painter. Therefore, the most gifted artists usually ended up creating paintings for the church.
Since the interior space of a church or cathedral was often massive, paintings that were displayed in these places had to be quite large, so that they could be seen by all who entered the sacred space.
During the heyday of religious art, painting took on a narrative quality, because in fact, the paintings became a visual interpretation of the Bible and a representation of the religious icons of the era.
During the Medieval to Renaissance era, painting and sculpture in southern Europe, where Catholicism prevailed, took on a different quality from paintings and sculptures that were created in northern Europe. Religious themes were definitely much more common in the southern region.
The depiction of the figure in three-dimensional form advanced rapidly during the Gothic and Renaissance eras, partly due to the demand for realistic portrayals of historical religious figures and living nobility. Also during this time frame, there was a movement away from purely religious art.