I often hear that the Greek/Romans were compelled to fight for honor and glory. Was this entirely for social purposes, i.e., to increase one's social standing and show other people how great you were, or was there a religious component to it as well? Did people in the ancient world believe their reward in the afterlife was based on how much honor/glory you achieved in this life? How did things change after the West became Christianized?
To be fair, honor and glory are important even today. The same words are used when citizens of a country talk about their armed forces today. Yes, there are those who don't like their country's military and by extension members of the armed forces but at the same time a vast majority probably regard joining the armed forces as an honorable act. Point here is that the reasons why one joined a military in antiquity is probably not a whole lot different from why one joins an army today.