Early Church Councils, Canons on Christians in the Military & War

The Apostolic Tradition of Hippolytus 215AD:

16.7 If someone is a gladiator, or one who teaches those among the gladiators how to fight, or a hunter who is in the wild beast shows in the arena, or a public official who is concerned with gladiator shows, either he shall cease, or he shall be rejected.

9 A military man in authority must not execute men. If he is ordered, he must not carry it out. Nor must he take military oath. If he refuses, he shall be rejected.

10 If someone is a military governor (has the authority of swords), or the ruler of a city who wears the purple, he shall cease or he shall be rejected.

Council of Nicea, Canon 12, 325AD:

"As for those who were called by grace and at first zealously threw away their military uniforms, but then later returned like dogs to their own vomit (so that some regained their military positions through bribes and gifts), let these spend three years as hearers and ten years as prostrators. But in all such cases it is necessary to carefully examine their intentions and their repentance. If they give evidence of their conversions by their actions (and not mere pretense), with fear, tears, perseverance, and good works, then they may properly join the assembly in prayers once they have fulfilled their appointed time as hearers. Beyond that, the bishop may make an even more lenient (philanthropion) decision concerning them. But those who take the matter with indifference, and who think the prescribed form of entering the church is sufficient for their readmission, must fulfill the whole time."

Basil of Caesarea, Canon 13, 370AD:

“Our Fathers did not consider murders committed in the course of wars to be classifiable as murders at all, on the score, it seems to me, of allowing a pardon to men fighting in defense of sobriety and piety. Perhaps, though, it might be advisable to refuse them communion for 3 years, on the ground that they are not clean-handed.”

Canon 43:

“He who gives a mortal wound to another is a murderer whether it is done in aggression or in self-defense."

St. Nicodemos, Interpretation of Canon 13 of St. Basil:

“By ‘Our Fathers" here Basil the Great means Athanasius the Great and his followers. For Athanasius says in his Epistle to Amun that for one to slay enemies in war is lawful and praiseworthy. But St. Basil explains also the reason why the more ancient Fathers permitted them to be pardoned, which is that those men who slay men in the course of war are fighting for the faith and for the maintenance of sobriety. For, if once the barbarians and infidels should succeed in gaining the upper hand, neither piety will be left, since they disregard it and seek to establish their own wicked faith and bad belief, nor sobriety and maintenance of honor, seeing that their victory would be followed by many instances of violation and ravishment of young women and of young men. The Saint goes on to add, however, on his own part, not a definitive Canon, but an advisory and indecisive suggestion that although these men who slay others in war were not considered murderers by the more ancient Fathers, yet, since their hands are not unstained by blood, it might perhaps be well for them to abstain from communion for 3 years solely as regards the Mysteries, but not to be expelled, that is to say, from the Church, like other penitents.”

The Testament of our Lord Jesus Christ, 350- 400AD:

Chapter 2: “If any one be a soldier or in authority, let him be taught not to oppress or to kill or to rob, or to be angry or to rage and afflict any one. But let those rations [Luke 3.14] suffice him which are given to him. But if they wish to be baptized in the Lord, let them cease from military service or from the [post of] of authority, and if not let them not be received.” 

Notes to Chapter 2: Forbidden Trades and Professions and Military Service in other Church Orders

(1) C.H. 65-79 have a long list of those who are not to be admitted…No man who has received the power of killing, or is a soldier, to be received…Christians are not voluntarily to become soldiers; if compelled, they must beware lest they be guilty of blood; if they have shed blood, they are not to receive Holy Communion till they repent.

(2) Eg. C.O. 41 headed “Of Actions and Works,”

A soldier being in authority…he who has the power of the sword or a city governor clothed with purple is to be rejected or else cease (from their profession). Catechumens or baptized persons wishing to be soldiers are to be rejected because they have despised God.

“Dark” to Medieval Age

Old Tesmanet Priesthood exempt from Military Service

Theology of the Old Testament, Gustav Friedrich Oehler, p 206.

The service of the Levites…is designated as military service [zaba, Num. 4.3, 30; 8.24 (in the camp of Jehovah, 1 Chron. 9.19)], and at a later period it was still organized entirely in a military manner.  

Dictionary of the Bible: Pleroma-Zuzim, Hastings, Selbie, Davidson, Driver, Swete, p 85.

There appears to be a special reference to the escorting of the sacred ark, which accompanied Israel in their journeyings and campaigns, in the remarkable term, likewise used very occasionally of the Levites’ service, zaba, ‘to render military service’ [Num. 4.23 al.].

The ‘tribe of Levi,’ i.e. probably the Levites and also the Aaronites, is exempted from being numbered amongst the children of Israel [Num. 1.49; 2.33], i.e. from military service.

Ellicott's Commentary for English Readers, Num. 4.3:

All that enter into the host.—Or, every one who enters upon the service. The word zaba, commonly rendered host, and used elsewhere to denote military service, is here used to denote the service of the sanctuary.

Cambridge Bible for Schools and Colleges, Num. 4.3:

[the service] This unusual meaning of the word which generally denotes ‘warfare’ or ‘host’ (R.V. marg.) is found again five times in this chapter (Numbers 4:23; Numbers 4:30; Numbers 4:35; Numbers 4:39; Numbers 4:43), and elsewhere only in Numbers 8:24 f., and of women in two very late passages, Exodus 38:8, 1 Samuel 2:22. It perhaps implies that the Levites formed an organized body appointed for God’s work under the command of superior officials, as were the rest of Israel who were numbered for war.

Greg Boyd, Gods’ Way of War:

"Yahweh forbade those who served as temple priests to engage in violence. When the New Testament later refers to the body of Christ as a royal priesthood, this is at least part of what it has in mind. While non-followers of Jesus may consider the use of violence in certain “justified” circumstances to be necessary, if not praiseworthy, the royal priesthood of Jesus followers are called and empowered to bear witness to God’s non-violent ideal by altogether abstaining from it."

http://reknew.org/2015/10/gods-way-of-war/#sthash.G4oiAPiE.dpuf

Historians on War and Violent Self-Defense

The First Missionary War, Chapter 1, Michael Routery, 1997:
“The Christian religion has, so often, spread through violence, force and coercion. Yet, its advocates, who have written the histories most of us learned in school, portray it as having been joyfully embraced by the ancient world, a loving embrace whose only restriction was imposed by the corrupt Roman state like a mean father with an innocent child…In truth, the Roman Church triumphed by marrying the Empire in that most fateful of centuries, the 4th [i.e., Nicea], and for the most part people converted because they were terrorized into doing so or forced to by ferociously repressive new laws…The new religion set itself apart from others, particularly, in its jealousy and extreme intolerance of any other spiritualties [i.e., paganism].”

The Founder’s Bible, Romans 13:

“Could Christian rulers prohibit other Christians from following what they believed to be clear scriptural teachings? …This question was addressed in American pulpits at the time. [Many believed that] God would not bless an offensive war. [Illustrative of this belief] was the famous command to the Lexington Minutemen, “Don’t fire unless fired upon!”

John Jay, “Founding Father”:

“It’s true that even just war is attended with evils and so likewise is the administration of government and of justice; but is that a good reason for abolishing either of them? They are means by which greater evils are averted…To prevent the incursion or continuance of evils, we must submit to the use of those means, whether agreeable or otherwise…”

Greg Boyd, Gods’ Way of War:

“Yahweh forbade those who served as temple priests to engage in violence [Num. 1-2; 4; 8]. When the NT later refers to the body of Christ as a royal priesthood, this is at least part of what it has in mind. While non-followers of Jesus may consider the use of violence in certain ‘justified’ circumstances to be necessary, if not praiseworthy, the royal priesthood of Jesus followers are called and empowered to bear witness to God’s non-violent ideal by altogether abstaining from it.”