Regarding Hebrews 13:13, why say that “outside the camp” means “outside the rest of Christendom?” The context of the entire book and the immediate context seems to be leaving the Mosaic/Judaistic system of worship.
I agree that this seems like an “off-the-wall” reference. However, I think I can explain why some speakers use this analogy.
It would be good to start with the general principle of separation from evil. This is a complex topic because there are various forms of evil and corresponding degrees of separation. In addition, because we are in the world there is some evil we cannot separate from. 1 Corinthians 5 is an important chapter because it speaks of separation from evil in the assembly and also points out that we cannot separate from all evil (1 Cor. 5:9-10). A person may even feel free to meet with Christians at work for a Bible study who hold various beliefs without being identified as one who holds erroneous beliefs himself. We should always use every opportunity to be of help to others so long as we can avoid being identified with their errors.
Separation is not only a New Testament concept. In fact, it goes all the way back to the first day of creation (Gen. 1:3-5). There God separated light from darkness. This is the primal representation of the principle we have in 2 Corinthians 6:14 where the apostle Paul asks: “what fellowship has light with darkness?” Israel was to be separate from the nations around them (Lev. 19:2, 20:7, 26). Their failure to maintain their unique witness for Jehovah eventually lead to their captivity. Then, although some of them returned for the advent of their Messiah, they rejected the Lord Jesus. Their unbelief confirmed their position outside God’s blessing (Jehovah had declared His people lo ammi meaning “not my people”, Hos 1:9). Yet, in the early Church period there were still Jewish Christians who continued to worship at the temple even though the Lord has said “your house is left unto you desolate”. (Mt 23:38) The book of Hebrews was written to these. The apostle calls them to “go to Him (Jesus) outside the camp.” The “camp” here clearly means the worship of Judaism, as your question suggests. They were being called to join the Christian company.
How does the church correspond to Judaism? First, we need to realize in this context “the church” refers not to the true church or Assembly, but to the professed church, or “Christendom.” This distinction is based on the observation from the epistles to Timothy. In 1 Timothy we have in view the “church of the living God” (1 Tim. 3:15) but in 2 Timothy we have in view “the great house” (2 Tim. 2:20). It is in this same chapter that we are enjoined to separate from those in the “great house” and “pursue righteousness, faith, love, peace, with those that call upon the Lord out of a pure heart.” (vs 22)
So, the parallel is between “Christendom” which consists of true believers and mere professing Christians, and Judaism which consists of true followers of the Messiah and Jews many of whom were complicit in crucifying the Lord. In this analogy, “the camp” represents professing Christians which mostly do not follow sound doctrine. It is solemn indeed that the Christian profession, which started out so well has degenerated into what it is today. But, above all, it must be remembered that the admonition is to “go forth to Him (Jesus)”. We are not to follow anyone else.
A quotation from another which may help explain this point:
The atmosphere of what is called a “Christian world” [or, professing Christianity] is more detrimental to the development of faith than the unbelieving world. That is because a Christian world promotes compromise, and compromise has in it disloyalty to Christ and to His word. In the Christian world, you are not faced with what is openly hostile to Christ. Open hostility would put you on your guard, and rouse up in you all your power of resistance. Instead, you find truth owned, but not taken very seriously. You are to follow it, but not be too extreme about it. And then, we naturally grow up to the stature, morally or spiritually, of the company we keep!
Thus, the application of “go forth unto him without the camp” is the admonition in 2 Timothy 2:22, “pursue righteousness, faith, love, and peace, along with those that call on the Lord from a pure heart” instead of remaining in the great house with dishonorable vessels.
 F. W. Grant, The Numerical Bible: The Gospels, (New Jersey: Loizeaux Brothers, 1977) 104. (Edited)
I really appreciated this Article/Question Answer thing today. It encouraged me, especially during this time with the new virus that is effecting our world, and just plain with the way our world is now. It reminded me that in this world where most of us might prefer to keep quiet about our faith, what the world needs is for me to step out of the pen and walk with my shepherd in the world to help the other lost sheep, and quit sitting around eating grass. Thank you all for your awesome work!
At this point in Hebrews, some commentaries and study Bibles will point the reader back to Exodus 33, since that’s where the concept of “outside the camp” originally came from. It’s also very significant for understanding what “outside the camp” means in spiritual terms. In parts of the New Testament, Israel’s journey through the wilderness is brought out as an example for God’s people in present days: we pass through this world as a spiritually desolate place. We interact with it in our day to day lives, and use whatever resources God gives to us. But we must not settle into it and get comfortable with its ways, because there is no spiritual food in it.
In Numbers 2, we read how God intended for the camp of Israel to be set up in the wilderness: the “tent of meeting” was to be in the center, and the tribes of Israel were to camp around it in an orderly way. The spiritual lesson is clear: God’s people should have God’s presence in their center, and fully acknowledge Christ’s authority in how we are “placed” in His Assembly.
But in Exodus 32, the people of Israel had corrupted their testimony and worshipped a golden calf. What was Moses’ response? He destroyed the physical idol, but in Exodus 33, it says he set the “tent of meeting” a good distance outside the camp, and if anyone wanted to inquire of God, they had to go outside the camp to that place. God was nearby, but he was not in the center of the camp where He should have been. Even though the physical idol had been judged and put away, it appears Moses recognized that the people’s hearts were still clinging to it.
When we realize that the passage in Hebrews is a “call-back” to all of this unhappy history, and that the Jewish Christians who were the primary audience were still very much familiar with the writings of Moses, it should be much easier to see how it applies to the Assembly (Church) generally. There are a many idols in “the camp” today, some of them quite literal including special garments and titles, statues of saints, written creeds and writings that are given as much authority as scripture itself, and other things like these. Other idols may not be so physical or visible, yet distract and occupy hearts with things other than the authority of Christ.
“The camp” rejected God’s authority in the wilderness, and Moses illustrated that plainly to the people, as Exodus 32-33 shows. It also rejected Christ and crucified Him outside the gate of Jerusalem, as the passage in Hebrews reviews. And today, there will be reproach for all who are likewise willing to go “outside the camp” that claims to belong to God, but does not completely acknowledge His sovereign authority.
So yes, the practical effect of Hebrews is that the Jewish Christians needed to move beyond the “camp” of Judaism, but the spiritual lesson underlying the statement goes much further!