To get an overall picture of the main theories we have seen so far, it is possible to group them into the different eras in which they were adopted. This overview facilitates the identification of their origin and the understanding of how they evolved chronologically in the theological context of salvation.
We can see how, over the centuries, the various theories have, in most cases, moved away from the original conceptions of the early Church. In fact, in the first centuries salvation was understood as a spiritual union with Christ such as to produce a radical transformation in the faithful, a profound moral change aimed at producing good fruits for the community, especially in favour of the weakest. Later, in the early Middle Ages, probably due to Roman pagan influences, salvation became a commercial and/or military matter, external and extraneous to the faithful, and included in the framework of the event only God and the devil. Finally, in the late Middle Ages, following the introduction of Aristotelian thought into Christianity, salvation became a legalistic accommodation within the Trinity, with a participation of man (in the version of Thomas Aquinas) or with a total exclusion of him (in the version of Luther and Calvin), thus very far from the original conceptions.
In the next chapter we will examine some modern theories that have been proposed since the nineteenth century, and which have in some way tried to recover some of the concepts that had been lost.