"Christian idolatry" sounds like an oxymoron, because Christianity is a monotheistic religion that teaches we should worship only the one true God. But ironically, Christians often find themselves in danger of creating and worshiping idols, even while they claim to be believers in Christ alone. This is what was happening to the Galatians in the first century--they had left false pagan gods for the true religion, but now were being drawn back into a form of idolatry by thinking they had to become more Jewish in their spiritual walk and worship.
And the same kind of thing can happen to us in the twenty-first century.
In Galatians 4:8-11, Paul writes, "Formerly, when you did not know God, you were enslaved to those that by nature are not gods. But now that you have come to know God, or rather to be known by God, how can you turn back again to the weak and worthless elementary principles of the world, whose slaves you want to be once more? You observe days and months and seasons and years! I am afraid I may have labored over you in vain."
Martin Luther summarizes Paul's message well in his commentary:
He tells them: "You have taken on teachers who intend to recommit you to the Law. By my doctrine I called you out of the darkness of ignorance into the wonderful light of the knowledge of God. I led you out of bondage into the freedom of the sons of God, not by the prescription of laws, but by the gift of heavenly and eternal blessings through Christ Jesus. How could you so soon forsake the light and return to darkness? How could you so quickly stray from grace into the Law, from freedom into bondage?"
Then Luther raises a really interesting question about the text, and answers it in a way that highlights not only the danger of Christian idolatry, but the profound truth that there really are only two religions in the world--one of grace (true Christianity) and one of works (every other belief system that exists). This is what makes the biblical gospel truly unique, and why getting it right is so important and necessary. Hear the great Reformer's comments about this...
Why does Paul accuse the Galatians of reverting to the weak and beggarly elements of the Law when they never had the Law? Why does he not say to them: "At one time you Galatians did not know God. You then served idols that were no gods. But now that you have come to know the true God, why do you go back to the worship of idols?" Paul seems to identify their defection from the Gospel to the Law with their former idolatry. Indeed he does. Whoever gives up the article of justification does not know the true God. It is one and the same thing whether a person reverts to the Law or to the worship of idols. When the article of justification is lost, nothing remains except error, hypocrisy, godlessness, and idolatry.
God will and can be known in no other way than in and through Christ according to the statement of John 1:18, "The only begotten Son, which is in the bosom of the Father, he hath declared him." Christ is the only means whereby we can know God and His will. In Christ we perceive that God is not a cruel judge, but a most loving and merciful Father who to bless and to save us "spared not his own Son, but gave him up for us all." This is truly to know God.
Those who do not know God in Christ arrive at this erroneous conclusion: "I will serve God in such and such a way. I will join this or that order. I will be active in this or that charitable endeavor. God will sanction my good intentions and reward me with everlasting life. For is He not a merciful and generous Father who gives good things even to the unworthy and ungrateful? How much more will He grant unto me everlasting life as a due payment in return for my many good deeds and merits." This is the religion of reason. This is the natural religion of the world. "The natural man receiveth not the things of the Spirit of God. (I Cor. 2:14.) "There is none that understandeth, there is none that seeketh after God." (Romans 3:11.) Hence, there is really no difference between a Jew, a Mohammedan, and any other old or new heretic. There may be a difference of persons, places, rites, religions, ceremonies, but as far as their fundamental beliefs are concerned they are all alike.
God never promised to save anybody for his religious observance of ceremonies and ordinances. Those who rely upon such things do serve a god, but it is their own invention of a god, and not the true God. The true God has this to say: No religion pleases Me whereby the Father is not glorified through His Son Jesus. All who give their faith to this Son of Mine, to them I am God and Father. I accept, justify, and save them. All others abide under My curse because they worship creatures instead of Me.
Without the doctrine of justification there can be only ignorance of God. Those who refuse to be justified by Christ are idolaters. They remain under the Law, sin, death, and the power of the devil. Everything they do is wrong. Nowadays there are many such idolaters who want to be counted among the true confessors of the Gospel. They may even teach that men are delivered from their sins by the death of Christ. But because they attach more importance to charity than to faith in Christ they dishonor Him and pervert His Word. They do not serve the true God, but an idol of their own invention. The true God has never yet smiled upon a person for his charity or virtues, but only for the sake of Christ's merits.
As we're thinking about Paul's and Luther's warnings (to professing believers!) about "inventing our own gods," I thought this would be a good place to reproduce something I wrote in a former post about the false gospels that even Christians can so often be influenced by...
The legality gospel. This is what the Paul and Luther were most concerned about in their times, and the problem still exists today in different forms. Something is added to grace and faith alone as necessary for us to be justified (declared righteous) before God. We are told that we cannot be saved without Roman Catholic sacraments, speaking in tongues, water baptism, membership in a specific church, or a plethora of other "works" that are stated or implied to be necessary additions to faith in Christ.
The morality gospel. This is similar to the first, but defined more by what is not included. Moral virtues and cultural values are encouraged, while Christ's atonement is minimized or even excluded. This kind of teaching has been called "Christless Christianity" and "Moralistic Therapeutic Deism," and has difficulty answering the question, "If your message was delivered in a Mormon Church (or even in a Muslim mosque), would anyone be offended by it?"
The immorality gospel. This is the opposite extreme from the first two, saying that our repentance and obedience to God's law is unnecessary as a consequence or proof of saving faith, or even undesirable because we might somehow become legalistic or moralistic. In other words, this false gospel says that people can be Christians and go to heaven even though they live a life of disbelief, disobedience and even disregard for what God has said in the Bible. But although we should never think of our good works as the cause of our justification, we must realize that they are always the inevitable consequence of it. As James said, faith without works is dead and cannot save.
The prosperity gospel. Earthly "health and wealth" are not what God promised in His gospel--in fact Jesus said "in this world you will have tribulation." That's not commonly thought of as one of God's promises, but it was. And it's more realistic (and consistent with the true gospel) to expect and even embrace suffering and self-denial as an essential part of our journey down the narrow road, which is the way of the cross rather than the couch.
The universality gospel. "All roads lead to heaven" is a slogan of this false teaching, which rejects the necessary element of exclusivity that is in almost all New Testament gospel passages (and illustrated repeatedly in the Old Testament). Jesus said, "I am the way, the truth, and the life; no one comes to the Father except through me," and anyone who contradicts that is promoting a damnable lie.
The individuality gospel. This is the idea, which has no precedent in Scripture or church history, that people can be Christians but have no connection to the visible church. Especially prevalent in American culture, this is tantamount to saying "I want God as my Father but I don't want to be in his family" (see 1 Timothy 3:15, where the local church is called the household of God).
The liberality gospel. This used to be called "the social gospel," but the primary purveyors of it have exchanged the term "socialism" for "liberalism." But they have continued to espouse the idea that salvation is essentially achieved by the practice and advocacy of works of mercy and social justice. They quote the Golden Rule, but fail to recognize that it is a summary of the law of God (which cannot save), and need to hear Luther on the crucial distinction between law and gospel.
The doctrinality gospel. While perusing our shelves of books recently, my wife unearthed one that had been given to us years ago by some friends. It was written by a pastor who taught that only Five-Point Calvinists are really saved....if people believed that Jesus died for everybody, for example, they were not trusting in Him alone and would be lost. Ironically, I fear that was an example of people trusting in their theology rather than in Christ alone. And I'm concerned that more subtle versions of this problem exist (especially among "Reformed" people), where we think "If anyone is saved, it's surely me" because we've come to a particular understanding of doctrinal truth.