The C-Spectrum is a practical tool some missionaries use to describe six types of Christian communities found in Muslim contexts. It is a coded scheme devised to see how contextualized one can become within Islam, even to the point of being considered a Muslim.

On the far left is C1, a traditional church that uses outward elements foreign to Muslim culture and considered Christian by both Christians and Muslims. On the far right is C6, supposed secret followers of Jesus but still considered Muslim by the Islamic community. Think of a C5 believer as one that makes a Muslim pause and tilt his head.

John Travis (a pseudonym) has written assiduously on this matter and is among the greatest proponents of what missiologists call the Insider Movement, a method of evangelizing Muslims that allows them to remain as active participants of Islam. Below is a summary of some C5 ideology.

Insiders Believe Religious Affiliation Doesn’t Matter

In his article, “Must all Muslims Leave Islam to Follow Jesus”, Travis tells of a question his daughter brought to him: “Daddy, can a Muslim go to heaven?”

I responded with an Acts 15:11-type ‘yes’: If a Muslim has accepted Isa (Jesus) the Messiah as Savior and Lord, he or she is saved, just as we are. We affirmed that people are saved by faith in Christ, not by religious affiliation. Muslim followers of Christ (i.e., C5 believers) are our brothers and sisters in the Lord, even though they do not change religions.

Let us keep our eye on the ball. No one is arguing against the opportunity that even the worst of sinners have for salvation. Those of any false religion will be granted eternal life based on the merits of Christ. But this girl’s question addressed the results of such a supposed conversion.

Suppose his daughter asked a similar question? “Daddy, if a Buddhist, atheist, or Satanist has accepted Jesus as Savior and Lord, can he be saved and not leave his religion?” If Travis answers yes, then he has no problem with Christians dabbling in the occult and denying God’s existence. If he answers no, then I wonder why a Satanist must leave his place of worship but a Muslim must not. This brings us to the crux of the issue.

This is not about evangelism for Muslims. Travis believes that there is enough redeemable truth in Islam to allow a Christian to remain in Islam. Peter’s words to Simon the sorcerer help us. After this magician “believed” and was “baptized” (Ac. 8:13), the apostle railed on him to repent of his wickedness (v. 22) because his behavior did not match his profession. Had Peter been asked if a sorcerer who believes in Christ can go to heaven while remaining a sorcerer, he would have replied: he has neither part nor lot in salvation (v. 21).

Insiders Argue that Many Muslims Affirm the Trinity

Travis writes: “the fact that over half [of C5 leaders] understand the Trinity well enough to affirm God as Father, Son, and Holy Spirit is actually astounding considering it would be considered apostasy by most Muslims!”

Even if we grant the veracity of this claim, it means that half of the movement Travis is asking us to embrace as a viable model of Christianity does not even believe in the Trinity. At the outset, then, half of the C5 “believers” are still under God’s judgment. This says nothing of the other half that, while they may embrace the Trinity, they may not accept other core Christian teachings that are necessary for salvation.

Insiders Prefer Not to Change Their Religion

Travis and other C5 proponents want to make Christianity as easy and attractive as possible. “The C5 approach, which communicates the message of salvation in Christ without the intent to persuade Muslims to ‘change their religion,’ might in fact be the one most appreciated by Muslims.”

If the effects of “easy-believism” were not bad enough within the US, an even more extreme form is now being peddled on the mission field. That Muslims would appreciate such an easy road to heaven is not under debate. But does it agree with the words of Jesus?

“Enter by the narrow gate. For the gate is wide and the way is easy that leads to destruction, and those who enter by it are many. For the gate is narrow and the way is hard that leads to life, and those who find it are few” (Mt. 7:13-14). Jesus never presented salvation as easy but rather as a fight and an agonizing struggle. “Strive (agōnizomai) to enter through the narrow door. For many, I tell you, will seek to enter and will not be able” (Lk. 13:24).

Insiders Believe the Qur’an Can Be Reinterpreted to Embrace the Crucifixion

Rather than interpreting the Qur’an as do most Muslims, Travis suggests Muhammad and the Qur’an can be “reinterpreted” to say that Jesus was really crucified after all. But how can the Qur’an be any clearer when it says that “they killed him not, nor crucified him, but so it was made to appear to them” (4:157,Yusif Ali)?

Even if a Muslim were to accept that Christ died, this is misleading because they most certainly would deny that there was any atonement on the cross. One Muslim with whom I was in formal debate told me that while a few Muslims may accept that Jesus died, no Muslim would accept that Jesus’ death on the cross could in any way atone for the sins of humanity.

Men like John Travis, Phil Parshell and Ralph Winter are playing on the ignorance that most Christians have of Islam and using ambiguous language to state the case that Muslims are really not that far from Christianity.

Insiders Believe the Un-evangelized May Go to Heaven

How is it that Muslims can be saved when only embracing a few fragments of Jesus’ teaching? Ralph Winter has used the story of Cornelius in Acts 10 to suggest we cannot be sure he was “hell-bound” before he heard the gospel from Peter. Winter, like many others, suggests that NT believers can be saved apart from the gospel.

But this story does show that faith in the death and resurrection of Christ is necessary for salvation. (1) The means by which Cornelius was saved was by the message that Peter preached (Acts 11:14). (2) Peter states that only the believer will have his sins forgiven (Acts 10:43). (3) God has also granted to the Gentiles repentance unto life” and eternal life is not given until one repents (Acts 11:18).

We can see, then, that the tentacles of C5 philosophy reach into many other biblical matters. Questioning the fate of the unevangelized, for example, is just around the corner.

Insiders are Salt and Light

Elsewhere, Travis remarks: “What we will argue, however, is that one way God is moving at this point in salvation history, is by sovereignly drawing Muslims to himself, revolutionizing them spiritually, yet calling them to remain as salt and light in their religious community of their birth.”

At first glance, his purpose sounds innocent: Muslim converts to Christianity should evangelize their people. But that is not all he is saying. C5 proponents want these converts to so “contextualize” with their Muslim brethren, remain so active in the mosque and religious life of Islam, that Muslims still see them as Muslims.

Ironically, Travis references the salt and light in Matthew 5:13-14 to substantiate Muslims laying low within the Islamic community. But this is the opposite of what Jesus taught. “You are the light of the world. A city set on a hill cannot be hidden.” When Jesus told his disciples not to put their lamp under a basket, he was not only forbidding Peter from eating with the Judaizers but forbidding Abu from praying in the mosque toward Mecca.

Insiders Accept Jesus as the Messiah

Is it coincidence that Insiders love referring to Jesus as “Messiah”? Not at all, for the Qur’an does as well. By using this title, Insiders are blurring the lines. They believe they have advanced in evangelism by speaking of their love for “Isa the Messiah”, somehow forgetting that the most ardent enemies of Christianity would speak the same way.

C5 proponents desperately want a form of Christianity that can coexist within the framework of Islam. They promote a repentance that is partial, when God says this is exactly what he will not allow. After the ninth plague, Pharaoh—so reluctant previously to repent—offered a compromise to Moses. “Go, serve the LORD, only let your flocks and your herds be kept back” (Ex. 10:24). But Moses was privy to Pharaoh’s manipulative ways, knowing full well the very thing he was unwilling to give up is what would eventually bring back Israel to Egypt. Moses said it was all or nothing (Ex. 10:25).