Saint Michael- Master of Belmonte late Fifteenth Century

Here we see Saint Michael throwing out Satan from heaven. Note that this piece was originally not seen in isolation but was viewed in a holy atmosphere with incense clerical outfits and other iconography.

Most people then being illiterate, learned informal catechism from these types of paintings.

Hence they were painted to be excessively graphic so that viewers would remember them even outside the church. Note the spear piercing the demon's lip. 

It is also interesting to see that the demon is made up of a host of smaller beings and demons that imaginatively comprise his body.