Both Islam and Mormonism depend on a similar claim: historic Christianity became corrupted and needed to be corrected by a later revelation.
Islam claims that Christians misunderstood or corrupted the true message of Jesus. The Qur’an denies central Christian doctrines such as the crucifixion of Christ in Qur’an 4:157, and Islamic theology often argues that the Gospel message preserved by Christians is no longer pure.
Mormonism makes an even more explicit restoration claim. It teaches that after the death of the apostles, the Church fell into a “Great Apostasy,” priesthood authority was lost, doctrine became corrupted, and true Christianity had to be restored through Joseph Smith in the nineteenth century.
But the problem is simple:
Jesus never said His Church would disappear.
In Matthew 16:18, Christ says:
“I will build my church, and the gates of Hades shall not prevail against it.”
This is not a weak promise. Jesus does not say, “I will build My Church, but it will collapse for centuries.” He does not say, “The gates of Hades will temporarily overcome it until a later prophet restores it.” He says the opposite: His Church will be built by Him, and the powers of death and darkness will not prevail against it.
Then, after His resurrection, Christ gives the Great Commission in Matthew 28:19–20, commanding the apostles to make disciples, baptize them, and teach them to observe all that He commanded. He then promises:
“And behold, I am with you always, to the end of the age.”
That phrase matters: to the end of the age.
Jesus does not promise to be with His Church only until the apostles die. He does not promise guidance for a few decades, followed by total doctrinal collapse. He promises His abiding presence until the end of history.
From an Orthodox Christian perspective, this does not mean every bishop, priest, council, emperor, or Christian community would be sinless or error-free. The Church has always fought heresy, corruption, political pressure, and human weakness. Scripture itself warns that false teachers would arise.
But there is a massive difference between saying, “There will be heresies and corruptions within history,” and saying, “The entire apostolic Church lost the true faith and had to be replaced or restored centuries later.”
The first claim is biblical.
The second claim directly conflicts with Christ’s promises.
If Islam is correct, then the Christian Church failed to preserve the truth about Jesus almost immediately. The apostles and their successors supposedly allowed the world to believe in a false crucifixion, a false resurrection Gospel, and a false identity of Christ for over six hundred years until Muhammad.
But the New Testament presents the crucifixion and resurrection as the heart of the apostolic Gospel. Paul writes in 1 Corinthians 15:3–4 that Christ died for our sins, was buried, and was raised on the third day. This was not a later corruption. It is the Gospel preached from the beginning.
If Mormonism is correct, then Christ’s Church lost priesthood authority, saving ordinances, doctrinal purity, and the fullness of the Gospel for roughly eighteen centuries. But if the Church truly vanished into total apostasy, then in what meaningful sense did the gates of Hades not prevail against it?
That is the unavoidable problem.
Mormonism and Islam both require Christians to believe that Christ founded His Church, promised to remain with it, promised that death and darkness would not overcome it — and then allowed it to be fundamentally corrupted for centuries.
That is not the biblical picture.
The biblical picture is continuity: Christ gives the faith to the apostles, the apostles hand it down, the Church guards the deposit, and Christians contend for “the faith once for all delivered to the saints” as Jude 1:3 says.
Paul tells Timothy:
“Guard the deposit entrusted to you.”
1 Timothy 6:20
And again:
“Follow the pattern of the sound words that you have heard from me… guard the good deposit entrusted to you.”
2 Timothy 1:13–14
The apostolic faith was not meant to disappear and be reinvented centuries later. It was meant to be preserved, guarded, taught, worshiped, and handed down.
That is why Matthew 16:18 and Matthew 28:20 are so powerful against both Islam and Mormonism. They do not merely defend “organized religion.” They defend the faithfulness of Christ Himself.
If Jesus built His Church, then His Church could be attacked, but not destroyed.
If Jesus promised to be with His disciples until the end of the age, then His presence did not vanish from history.
If the gates of Hades would not prevail, then no later prophet, angel, book, or restoration movement has the authority to claim that the apostolic Church was overcome.
The issue is ultimately not whether Christians have sinned. They have.
It is not whether false teachers appeared. They did.
It is not whether reform and repentance have been needed throughout history. They have.
The issue is whether Jesus failed to preserve His Church.
And the answer of Matthew 16:18 and Matthew 28:20 is clear:
No. Christ did not abandon His Church.