One of the more interesting developments surrounding the formulation of Just War Theory (e.g. the perimeters that outline when warfare and the killing of one’s enemies is justifiable) was how it was also used cement the divide that had been growing between clergy and laity throughout the first 300 years of the Church.
From Genesis to Revelation the people of God are called a “kingdom of priests.” The day of Pentecost in Acts 2 magnifies this reality with the anointing of the Holy Spirit being poured out on all believers; young and old, male and female, slave and free (not merely kings, high priests, and prophets). The Church community is a priesthood of believers. Yet, this does not mean that all believers are leaders. The New Testament writings acknowledge several different leadership roles that existed in the Church (i.e. Apostle, Elder, Deacon) and outline that these leaders, must among other qualities, be people of exemplary character. How each of these different leadership roles functioned is an issue of great debate throughout Church history. Not to mention that as changes in culture have introduced new forms of social orders and political governance the conversation concerning the structure of Church leadership and forms of Church governance have continued. (This is a topic for further conversation elsewhere.)
The vocational demands of ministry, the call of exemplary character among Church leaders, and the culturally influenced structures of Church governance were all sources of the fracture that was forming between clergy and laity. Then Just War Theory was introduced. It is a theory that began with Ambrose and would ultimately be clarified by Augustine in the 4th century. The theory framed warfare and killing justifiable under particular circumstances and held participants in a military conflict to certain standards of conduct. Just War Theory stood in opposition to the Church’s founding ethical convictions outlined by the words of the Church fathers and exhibited by the martyrs who both clung to Jesus’ teaching on the Sermon on the Mount (Matthew 5-7). Jesus taught, and the early Church strongly defended, the uncompromising command to abstain from violence and the call to love one’s enemies. Just War Theory’s introduction, therefore, not only served to establish an alien practice within the Church, it also served as one of the critical defining points that mark the division of clergy and laity into two classes of Christians, each with distinct expectations as disciples.
As the cultural pressure to accept the necessity of war mounting with foreign armies threatening Rome, the Church leveraged the growing divide between clergy and laity to adopt and implement the framework of Just War. The Church concluded that laypersons were allowed to participate in military service and bloodshed, as they were deemed unable to uphold the high moral standard of the Sermon on the Mount. Clergy, however, would remain forbidden to participate in warfare or to bear arms at all. Clergy and laity had undeniably fissured into two distinct classes of Christians.
Then, centuries later as the Protestant Reformation was igniting debates and fracturing the Church—by addressing many of the abuses of the Church—the concept of the priesthood of all believers was refreshed and given new life. In spite of this, the Church as a whole never returned to Jesus’ teaching on non-violence as a standard for all Christians. At best, different groups left the matter of non-violence and participation in wars up to the conscience of individual believers. Although, it is interesting to note that the Orthodox Church still retains the policy that forbids the bearing of arms to its clergy and does not allow a man to continue in the ministry who has shed blood.