Who is church history’s most notorious false teacher?It might not be possible to answer that question definitively. But if we were to create a top-ten “most wanted” list, the name Arius would undoubtedly be near the top.In ancient times, Arius’s teachings presented the foremost threat to orthodox Christianity — which is why historians like Alexander Mackay have labeled him “the greatest heretic of antiquity.” None other than Martin Luther said this about Arius:

The heretic Arius [denied] that Christ is true God. He did much harm with his false doctrine throughout Christendom, and it took four hundred years after his death to combat its injurious influence, yea, it is not even yet fully eradicated. In the death of this man the Lord God exalted His honor in a marvelous manner.

In case his name doesn’t sound familiar, Arius was a famous fourth-century false teacher who taught that the Son of God was a created being. Consequently, Arius denied Christ’s equality with God the Father, and along with it, the doctrine of the Trinity. Essentially, he was the original Jehovah’s Witness. His views were very popular during his lifetime and for many years afterward, even though they were denounced at the Council of Nicaea in 325 (and again at the Council of Constantinople in 381). Athanasius, the bishop of Alexandria, stood strongly opposed to Arius’s anti-Trinitarian teachings. That courageous stand proved costly for Athanasius — he was exiled from Alexandria five different times because he refused to compromise. Yet, during his forty-five years of ministry, Athanasius held the line of orthodoxy without wavering. As a result, in God’s providence, the truth about the Trinity was faithfully passed down to subsequent generations.Arius died in 336, just eleven years after the Council of Nicaea. Significantly, the account of his death comes from none other than Athanasius. In a letter Athanasius wrote many years after the fact, the Alexandrian bishop not only explained how Arius died, but also extrapolated on why he died. I think you’ll agree it’s a pretty dramatic story.* * * *Athanasius on the death of Arius (in a letter to fellow pastor)You have asked me to tell you about the death of Arius.I debated with myself for a long time about whether or not to give you an answer, afraid that someone might assume I was taking pleasure in his death. But, since there has been a debate among your colleagues concerning the Arian heresy — in which the question was raised as to whether or not Arius was restored to the church before he died — I think it is necessary to give an account of his death. That way your question will be put to rest, and, at the same time, it will silence those who are contentious. My guess is that, when the incredible circumstances surrounding his death become known, even those who raise such questions will no longer doubt that the Arian heresy is hateful in the sight of God.I was not in Constantinople when he died, but Macarius the presbyter was there, and I heard about what happened from him.Arius, on account of his politically-powerful friends, had been invited to appear before the emperor Constantine. When he arrived, the emperor asked him whether or not he held to the orthodox beliefs of the universal church. Arius declared with an oath that he did, and gave an account of his beliefs in writing. But, in reality, he was twisting the Scriptures and not being honest about the points of doctrine for which he had been excommunicated.Nonetheless, when Arius swore that he did not hold the heretical views for which he had been excommunicated, Constantine dismissed him, saying, “If your faith is orthodox, you have done well to swear; but if your beliefs are heretical, and you have sworn falsely, may God judge you according to your oath.”When Arius left the emperor, his friends wanted to immediately restore him to the church. But the bishop of Constantinople (a man named Alexander), resisted them, explaining that the inventor of such heresies should not be allowed to partake in communion. But Arius’s friends threatened the bishop, saying, “In the same way that we brought him to the emperor, against your wishes, so tomorrow — though it be contrary to your wishes — Arius will have communion with us in this church.” They said this on a Saturday.When Alexander heard this, he was greatly distressed. He went into the church and stretched out his hands before God, and wept. Falling on his face, he prayed, “If Arius is allowed to take communion tomorrow, let me Your servant depart, and do not destroy that which is holy with that which is unholy. But if You will spare Your church (and I know that You will spare it), take note of the words of Arius’s friends, and do not give Your inheritance to destruction and reproach. Please remove Arius from this world, lest he should enter the church and bring his heresy with him, and error would be treated as if it were truth.” After the bishop finished praying, he retired to his room deeply concerned.Then an incredible and extraordinary thing happened. While Arius’s friends made threats, the bishop prayed. But Arius, who himself was making wild claims, unexpectedly became very ill. Urged by the necessities of nature he withdrew, and suddenly, in the language of Scripture, “falling headlong, he burst open in the middle,” and immediately died where he lay. In an instant, he was deprived not only of communion, but of his very life.That was the end of Arius.His friends, overwhelmed with shame, went out and buried him. Meanwhile, the blessed bishop Alexander, amidst the rejoicing of the church, celebrated communion on Sunday with holiness and orthodoxy, praying with all the brethren. They greatly glorified God, not because they were taking joy in a man’s death (God forbid!), for “it is appointed for men once to die,” but because this matter had been resolved in a way that transcended human judgments.For the Lord Himself had judged between the threats of Arius’s friends and the prayers of the bishop Alexander. He condemned the Arian heresy, showing it to be unworthy of communion with the church. God made it clear to everyone, that although Arianism might receive the support of the emperor and even all mankind, yet it ought to be condemned by the church.(Note: I’ve updated and paraphrased the story in a few places for the sake of readability. Those interested can find Philip Schaff’s original translation here.)