Catechism lesson 29: The keys of the kingdom (LD 31)

The kingdom of God is open to believers and closed to unbelievers. In the life of the church, the opening and closing happens through the preaching of the gospel and church discipline.

LD 31 q&a 83.

What are the keys of the kingdom of heaven?

The preaching of the holy gospel
and church discipline.

By these two the kingdom of heaven
is opened to believers
and closed to unbelievers.

LD 31 q&a 84.

How is the kingdom of heaven
opened and closed
by the preaching of the gospel?

According to the command of Christ,
the kingdom of heaven is opened
when it is proclaimed and publicly testified
to each and every believer
that God has really forgiven
all their sins
for the sake of Christ’s merits,
as often as they by true faith
accept the promise of the gospel.

The kingdom of heaven is closed
when it is proclaimed and testified
to all unbelievers and hypocrites
that the wrath of God
and eternal condemnation
rest of them
as long as they do not repent.

According to this testimony of the gospel,
God will judge
both in this life
and in the life to come.

LD 31 q&a 85.

How is the kingdom of heaven
closed and opened
by church discipline?

According to the command of Christ,
people who call themselves Christians
but show themselves to be un-christian
in doctrine or life
are first repeatedly admonished
in a brotherly manner.

If they do not give up
their errors or wickedness,
they are reported to the church,
that is, to the elders.

If they do not heed
also their admonitions,
they are forbidden the use of the sacraments,
and they are excluded by the elders
form the Christian congregation,
and by God himself
from the kingdom of Christ.

They are again received
as members of Christ
and of the church
when they promise and show
real amendment.

A Biblical expression

The term “keys of the kingdom of heaven” comes directly from the Bible. In Mat 16:19, Jesus said to Peter:

I will give you the keys of the kingdom of heaven, and whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven.

What is the idea of the “keys”? What does it mean to have “the keys of the kingdom of heaven”?

So the church, through its leadership, was instructed to open and close the door of God’s kingdom. That is a serious task! It is a little puzzling why Jesus talks about “binding” and “loosing”. But the idea seems to be that when the church declares the door open to people, they can enter the kingdom of God and have eternal life; and when the church declares the door shut to people, they cannot enter the kingdom of God and will be lost.

This is a great responsibility. The Roman church has understood this verse as saying that the church is in charge of the grace of God, and that the pope (supposedly as successor of Peter) is the highest authority. But people, even church leaders, can be wrong. Is it all up to fallible people, then? In the Reformed churches, we emphasize that the Lord Jesus is the one who really holds the keys. We may only work on his behalf, declaring the kingdom of heaven open to believers and declaring it closed to unbelievers. The ultimate judgment is up to him.

The catechism states that there are two “keys”, two ways in which the church on behalf of Jesus declares the kingdom of heaven open and closed.

The preaching of the gospel

The first key is the preaching of the gospel. The gospel tells us that Jesus is the Saviour of sinful people. But the gospel also wants an answer. Will you believe, or won’t you? If you believe in the Lord Jesus, you will indeed be saved. If you don’t believe, you cannot be saved.

Through that message, the gospel opens and closes the door of heaven. It tells believers: “Yes, come in, your sins are forgiven, and you may live with the Lord forever.” It tells unbelievers: “Because you reject the Lord Jesus, you must stay outside of his holy kingdom.” A faithful preacher will clearly communicate this message off the pulpit.

Q&a 84 says that God will judge people “according to this testimony of the gospel”. Ultimately, it is not the preacher, but the gospel that declares the gospel open or closed.

Church discipline

The second key is church discipline. In q&a 85, the catechism echoes what Jesus said in Mat 18:15-18:

If your brother sins against you, go and tell him his fault, between you and him alone. If he listens to you, you have gained your brother.
But if he does not listen, take one or two others along with you, that every charge may be established by the evidence of two or three witnesses. If he refuses to listen to them, tell it to the church.
And if he refuses to listen even to the church, let him be to you as a Gentile and a tax collector.
Truly, I say to you, whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven.

The last sentence repeats the idea of the “key” of the kingdom: if a sinner refuses to listen to the church and repent, then the church must declare that the kingdom of heaven is closed to him.

We often use the word “church discipline” for the official actions taken by the consistory. But there is more to church discipline. If anyone thinks that a fellow Christian is sinning, he or she should address this personally first. Only when this has no effect, the elders of the church should become involved. The elders first work with the church member in an informal way.

But eventually, formal, official steps of church discipline are taken. In Reformed churches, there are five steps to this process. In the Canadian Reformed federation, the steps are as follows (Church Order, Art. 68, p. 658 of the Book of Praise):

Any one who obstinately rejects the admonition by the consistory or who has committed a public sin shall be suspended from the Lord’s supper. If he continues to harden himself in sin, the consistory shall so inform the congregation by means of public announcements, in order that the congregation may be engaged in prayer and admonition, and the excommunication may not take place without its cooperation.
In the first public announcement the name of the sinner shall not be mentioned.
In the second public announcement, which shall be made only after the advice of classis has been obtained, the name and address of the sinner shall be mentioned.
In the third public announcement a date shall be set at which the excommunication of the sinner shall take place.

The excommunication is an official declaration that the sinner is no longer a member of the church, and is excluded from the kingdom of heaven, until he or she truly repents from sin.

Some people think that it is cruel to excommunicate people so publicly. But it has to be clear that the Christian church is all about Jesus Christ; people who openly disrespect and disobey the Lord, may no longer call themselves Christians.

Marks of the true church

In Lord’s Days 25-31 of the Heidelberg Catechism, we discussed the means of grace and the keys of the kingdom of heaven. They describe essential activities of the church of Jesus. If a church fails to use the means of grace, or to use the keys of the kingdom, it can no longer truly be the church.

In Article 29 of the Belgic Confession, an important document in the Reformed churches, this is stated clearly.

The true church is to be recognized by the following marks:

It practises the pure preaching of the gospel.
It maintains the pure administration of the sacraments as Christ instituted them.
It exercises church discipline for correcting and punishing sins.

In short, it governs itself according to the pure Word of God,
rejecting all things contrary to it
and regarding Jesus Christ as the only Head.

Pure preaching, proper sacraments, and church discipline—these are the marks of the true church. We have not chosen these three things at random, but because Jesus told us to do these them.


  1. When preaching the gospel to unbelievers, is it a good idea to emphasize that the kingdom of heaven is closed for unbelievers? Why, or why not?
  2. When preaching to a church full of believers, is it necessary to warn that the kingdom of heaven is closed for unbelievers? Why, or why not?
  3. Suppose a minister or elders visits a church member and admonishes him because of sinful behaviour. The man responds: “That is none of your business; it is between God and me.” What would you say about that situation?
  4. When the church order talks about church discipline, it mentions two purposes of punishing sin. What are these two purposes? (Can. Ref. church order Art. 66)
  5. The church order requires that the second public announcement of church discipline can only be made with permission of the classis. (The classis is a meeting of ministers and elders from several other churches in the area.) Why do you think this is the case?
  6. To summarize: In what Bible passages did Jesus clearly command us to (1) preach the gospel, (2) baptize, (3) celebrate the Lord’s Supper, and (4) discipline sinners?


All: Memorize q&a 83.

Older students: Also memorize q&a 84.

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