How do believers in the Great Apostasy reconcile their views with Matthew 16:18?

The problem is with your interpretation of two things in Matt. 16:18. Firstly, if you believe Peter is the rock to which Jesus referred, well, then you do have a problem. But if you believe Jesus referred to what Peter said about Him as the Son of God, then the problem is a lot easier to solve.

Secondly, if you believe that Jesus was refering to a particular church institution, you have a problem. But, if you understand church as refering to any body of believers who believe what Peter said, the problem can be solved.

Jesus referred to the divine revelation that was made to Peter about Him as the rock on which all who believe in Him is built and against that revelation about Jesus the gates of hell have not prevailed - not even the apostasy of the RCC could prevail against it and that is why we still believe what Peter said about Jesus to this day.

OP---Question: according to believers in the Great Apostasy of the Church, how can there be a Great Apostasy if the Church is built on a rock against which the gates of hell shall not prevail?

Whether one believes the rock is Peter and his successors or the confession Peter and successors make, the answer is fairly straightforward.

And I tell you, you are Peter, and on this rock I will build my church, and the gates of hell shall not prevail against it. (Matthew 16:18 ESV)

Jesus is speaking the future tense about building His church and the gates of hell not prevailing against it. Once Christ suffered, died, was buried, and resurrected, then things changed.

I [Christ Jesus] am he that liveth, and was dead; and, behold, I am alive for evermore, Amen; and have the keys of hell and of death. (Rev 1:8)

In short, there will be (or is or has been) an apostasy, but thank God, it is Jesus who holds the keys to the gates of hell. We may all fall away, but Jesus will not. Jesus has the keys to hell. Therefore, the gates of hell will never prevail.

EDIT TO ADD RE COMMENT ABOUT Mat 16:19

The OP was about verse 18 (And I say also unto thee, That thou art Peter, and upon this rock I will build my church; and the gates of hell shall not prevail against it.) not about 19 (And I will give unto thee the keys of the kingdom of heaven: and whatsoever thou shalt bind on earth shall be bound in heaven: and whatsoever thou shalt loose on earth shall be loosed in heaven.) and whether it or the two verses even relate. In other words, yes there are two sets of keys; verse 18's set is about the keys to the gates of hell (verse 18) and 19's is about the keys to the kingdom.

Jesus descended to hell and opened the gates (see Apostles Creed and Scripture). Jesus. Not Peter, Paul, Mary, or anyone else. No one has that set per Scriptures as I quoted.

As to the keys to the kingdom of heaven, frankly, this is beyond the scope of the OP, but to make it clear. Jesus said I (Himself) will build My church. The gates of hell will not prevail (because Jesus kept the keys).

In verse 19, Jesus tells Peter that He will give Peter the keys to the kingdom (after His resurrection). What does that mean? Peter preaches to the Jews and Gentiles about the Good News first. Boom. The doors to the kingdom of heaven are now open.

PS It is a sad state of affairs for those who preach and teach that they or their Church have the keys to hell, rather than Jesus.

PPS Talk about apostasy to assert your Church has the keys to hell that you may open and shut, thrawting the Good News. Scripture is clear about who holds those keys and it ain't you. Or to assert your Church has the keys to the kingdom of heaven, usurping the singular initial push from Jesus to Peter.

Hope this helps answer the OP question. Jesus has the keys and therefore the gates of hell cannot ever prevail.

Matthew 16:18 is not relevant to the question of the 'Great Apostasy' for one reason. In this conflict between the Church and the "gates of Hell", the Church is not the defender. Hell is the defender!

The language at least in English could be understood either way, and for many years I always assumed that the Church would be in a defensive stance as it was attacked by hellish spiritual forces. But if you consider the Great Commission it makes sense to reverse these roles. It is the Church on the offensive, claiming back the world from hellish spiritual forces.

Taken this way, any Great Apostasy simply occurs on the defending side of this conflict.

• How can there be a Great Apostasy if the Church is built on a rock against which the gates of Hades shall not prevail?

If one understands that the Church is not the huge collection of denominations that call themselves Christian, but a very much smaller group of people that follow the teachings of Christ, then it becomes much more obvious.

Jesus and the Apostles knew that the true Church would remain a small flock throughout this age, and that a false Christianity would arise, deceiving almost the entire world.

I've written elsewhere:

Jesus himself had been aware that this falling away would happen: "Take heed that no man deceive you. For many shall come in my name saying that I am Christ, and shall deceive many." The original Apostles could see what was happening, and exhorted true Christians not to be misled.

Paul wrote: "I am astonished that you are so quickly deserting the one who called you to live in the grace of Christ and are turning to a different gospel, which is really no gospel at all. Evidently some people are throwing you into confusion and are trying to pervert the gospel of Christ.". He also knew that it would get worse after his own death: "For I know this, that after my departing shall grievous wolves enter in among you, not sparing the flock. Also of your own selves shall men arise, speaking perverse things, to draw away disciples after them.".

Peter too was concerned: "But there were false prophets also among the people, even as there shall be false teachers among you, who privily shall bring in damnable heresies ... . And many shall follow their pernicious ways ...".

The teachings of Jesus were turned into teachings about Jesus; the messenger became more important than the message. "For such are false apostles, deceitful workers, transforming themselves into the apostles of Christ. And no marvel; for Satan himself is transformed into an angel of light. Therefore it is no great thing if his ministers also be transformed as the ministers of righteousness; whose end shall be according to their works."

For a century after the Bible was written, there is a period in history where almost no recordings of the early Church exist. Later writers refer back to this time, but all records seem to have disappeared or been destroyed. Writer Edward Gibbon wrote: "The scanty and suspicious materials of ecclesiastical history seldom enable us to dispel the dark cloud that hangs over the first age of the Church".

It will remain small until the end-times, but God's true Church, founded on the Rock, will prevail until the end.

TLDR: The "rock" that Christ spoke in Matthew 16 is the personal revelation that Peter had from the "Father which is in Heaven" that Jesus is the Son of God. Those who receive personal revelation cannot fail. Christ gave Peter Preisthood Keys to orchestrate the affairs of the church. These keys were lost during the apostasy and eventually restored again through modern prophets. (See video for explanation!. Read also this, or this).

Long version:

Being a member of The Church of Jesus Christ of Latter-day Saints, and having been a missionary sharing the message of the Great Apostasy and restoration of Christ's Church through modern prophets, this question is vital to my Christianity and knowing where to go for essential ordinances like baptism and the Sacrament. (I speak of my own accord and not on behalf of the Church of Jesus Christ.)

To understand this phrase "upon this rock", we must consider the full context.

1. What is the "rock"?
2. What are the keys of the Kingdom?
3. How were they lost and restored?

With full context, we see that the "rock" is personal revelation.

13 ¶ When Jesus came into the coasts of Cæsarea Philippi, he asked his disciples, saying, Whom do men say that I the Son of man am? 14 And they said, Some say that thou art John the Baptist: some, Elias; and others, Jeremias, or one of the prophets. 15 He saith unto them, But whom say ye that I am? 16 And Simon Peter answered and said, Thou art the Christ, the Son of the living God. 17 And Jesus answered and said unto him, Blessed art thou, Simon Bar-jona: for flesh and blood hath not revealed it unto thee, but my Father which is in heaven. 18 And I say also unto thee, That thou art Peter, and upon this rock I will build my church; and the gates of hell shall not prevail against it. 19 And I will give unto thee the keys of the kingdom of heaven: and whatsoever thou shalt bind on earth shall be bound in heaven: and whatsoever thou shalt loose on earth shall be loosed in heaven.

The context for this quote is vital. First, Christ was challenging his disciples the source for their knowledge. While many rely on intellect or what-someone-else-told-them for knowledge, Peter knew by personal revelation that Christ was the Son of God.

Putting this in today's context, let's imagine Christ was homelessly traveling from town to town with a rag-tag band of followers. How would we be able to know Him as the Christ? The only way is by revelation, by knowledge which comes from "my Father which is in heaven."

The Church of Jesus Christ was, has been, and will be guided by personal revelation and Priesthood Keys.

1. Christ gave Peter the Priesthood of God through the laying on of hands (Matthew 10:1)
2. Priesthood is the "authority act in His name for the salvation of His children" (True to the Faith). Consider why Christ traveled far to be baptized of John? John was authorized.
3. Priesthood Keys "are the rights of presidency, or the power God gives to man to govern and direct the kingdom of God on the earth"

Christ was the one authorized to exercise the Priesthood Keys he held. When he died, the authority to exercise those keys were bestowed upon Peter. It was then through Peter and others authorized that believers were able to be baptized by.

Consider it for a moment - Christ was baptized by John before He built His church. Then he authorized Peter and the twelve apostles to baptize and to lay on hands. This was Christ setting up His church apart from the other baptisms that existed in the time. Baptism is one covenant and ordinance necessary to enter the Kingdom of God. Peter had the authority to determine how baptism would be administered.

Peter led the church by revelation (see Acts 10:15 for how he received by revelation word that it was now okay to eat "four-footed beasts" and other things (Acts 10:12)).

What about "the gates of hell"?

Those who have personal revelation in Him cannot fall. See John 6 when many disciples walked no more with Christ after he preached the sermon on his flesh and blood. Those who walked away lacked the personal revelation to know that Christ had the words of life. The gates of hell prevailed that day against those who were without a testimony similar to Peter's.

How did the apostasy begin?

Christ taught in Matthew 24:9-11:

9 Then shall they deliver you up to be afflicted, and shall kill you: and ye shall be hated of all nations for my name’s sake. 10 And then shall many be offended, and shall betray one another, and shall hate one another. 11 And many false prophets shall rise, and shall deceive many.

Paul prophesied that when he died there'd be a falling away of the church Acts 20:28-30.

28 ¶ Take heed therefore unto yourselves, and to all the flock, over the which the Holy Ghost hath made you overseers, to feed the church of God, which he hath purchased with his own blood. 29 For I know this, that after my departing shall grievous wolves enter in among you, not sparing the flock. 30 Also of your own selves shall men arise, speaking perverse things, to draw away disciples after them.

And in 2 Thessalonians 2:1-12:

3 Let no man deceive you by any means: for that day shall not come, except there come a falling away first, and that man of sin be revealed, the son of perdition; 4 Who opposeth and exalteth himself above all that is called God, or that is worshipped; so that he as God sitteth in the temple of God, shewing himself that he is God.

Clearly, there was a prophesied falling away. It began with the murdering of the apostles, as prophesied. The church would be taken away until the "restitution of all things" (Acts 3:19-21).

How was the Priesthood restored?

Happy to dive into this more, but see "Restoration of the Priesthood" and "The Keys and the Authority of the Priesthood". The keys were restored through a prophet who was chosen by God. Abraham was chosen. Moses was chosen in the bush. Christ chose Peter. Likewise, Christ chose Joseph Smith in 1820. Several years later he was given the Priesthoods of Aaron (by the hand of John the Baptist, see also this history) and of Melchizedek (by the hands of Peter, James, and John and this history).

Other Christian denominations consider Joseph Smith a fraud, or a mastermind, or whatever they want to call him (except a prophet of God). That's fine for them to say, but it doesn't actually make it so. Joseph's church still stands, the Book of Mormon remains an additional Testament of Jesus Christ (in addition to the New and Old Testaments).

How can I be saved from personal apostasy?

The core foundation of being a member of The Church of Jesus Christ of Latter-day saints is 1) a belief in God, 2) a belief in Jesus Christ as God's Son, and 3) knowledge of these things by the power of the Holy Ghost.

The only way you can know which church is Christ's church is by following Joseph Smith's example and praying to God the Father yourself and asking Him which church you should join. I implore any reading this to ask God themselves what Church is true. Don't rely on this text or on anyone you listen to. Because there is strong logic and reason in many religions or pastors. And while strong logic and reason could have led Peter to believe Christ was the Son of God, Peter knew only because of personal revelation. And so, may we all pray to God for His guidance to His church.

More details

Great Apostasy and the Restoration