Because of our sinful nature, the earthly church cannot be united until Christ returns?

"Because of our sinful nature, the earthly church cannot be united until Christ returns." 

The statement is only partly true, but seriously misleading if it is used to excuse division.

It is true that the earthly church will never achieve perfect, sinless, conflict-free unity before Christ returns. Christians still have sinful natures, different levels of maturity, different backgrounds, and sometimes genuine disagreements.

But it is not true that therefore the church cannot be united on earth. The New Testament repeatedly commands the church to pursue, preserve, and demonstrate unity now. Christian unity is not something postponed until Christ returns; it is something Christ has already created and the church is commanded to maintain.

1. Christ has already made His people one

Paul does not say, "You will become one when Christ returns." He says:

"For he is our peace, who hath made both one, and hath broken down the middle wall of partition between us."
— Ephesians 2:14

Notice the language: Christ has made both one.

The unity of the church is first God's work in Christ. Jews and Gentiles who were formerly separated have been brought together into one new humanity.

Paul continues:

"So then you are no longer strangers and aliens, but you are fellow citizens with the saints and members of the household of God."
— Ephesians 2:19

Therefore, Christian unity is not merely an ideal for heaven. It is already a spiritual reality in Christ.

The question is whether the church will live according to that reality.

2. Paul commands Christians to maintain unity

This is especially clear in Ephesians 4.

Paul says:

"I therefore... beseech you that ye walk worthy of the vocation wherewith ye are called,
With all lowliness and meekness, with longsuffering, forbearing one another in love;
Endeavouring to keep the unity of the Spirit in the bond of peace."
— Ephesians 4:1–3

The important word is "keep."

Paul does not say:

"Wait until Christ returns and then you will have unity."

He says:

"Endeavouring to keep the unity of the Spirit."

The unity already exists through the Holy Spirit. The church's responsibility is to preserve and express that unity.

And Paul immediately gives the theological foundation:

"There is one body, and one Spirit...
One Lord, one faith, one baptism,
One God and Father of all."
— Ephesians 4:4–6

That is remarkably strong.

One body.
One Spirit.
One Lord.
One faith.
One baptism.
One Father.

The church does not create these things. God has already given them.

3. Sin makes unity difficult—not impossible

This is where that statement contains an important truth but reaches the wrong conclusion.

Because of sin, Christians will have:

• disagreements,
• misunderstandings,
• pride,
• personality conflicts,
• cultural differences,
• different theological judgments,
• failures of love,
• and sometimes serious doctrinal error.

But the New Testament does not respond by saying, "Therefore division is inevitable and acceptable."

It says:

Forgive.

"Forgiving one another, if any man have a quarrel against any."
— Colossians 3:13

Bear with one another.

"Forbearing one another in love."
— Ephesians 4:2

Be patient with one another.

Seek reconciliation.

Speak the truth in love.

"Speaking the truth in love, may grow up into him in all things, which is the head, even Christ."
— Ephesians 4:15

And Jesus Himself prayed for His disciples:

"That they all may be one; as thou, Father, art in me, and I in thee."
— John 17:21

That prayer is not merely about heaven. Jesus explicitly connects the church's unity with its witness to the world:

"that the world may believe that thou hast sent me."

So church unity is part of the church's mission and testimony.

4. "We cannot be perfectly united" is different from "we cannot be united"

This distinction is crucial.

There is a difference between:

Perfect unity:
No sin, no disagreement, no misunderstanding, no doctrinal dispute.

and

Christian unity:
Different believers living together in Christ, loving one another, worshipping together, forgiving one another, bearing with one another, and maintaining fellowship around the truth of the gospel.

The first awaits the consummation.

The second is commanded now.

In fact, saying, "Because we are sinful, unity is impossible," can become a dangerous theological excuse.

Imagine applying that reasoning to forgiveness:

"We are sinners, therefore we cannot forgive until Christ returns."

Or to love:

"We are sinners, therefore we cannot love one another perfectly until Christ returns."

Or holiness:

"We are sinners, therefore we cannot pursue holiness until Christ returns."

That is not how the New Testament works.

Our imperfection is the reason we need grace and obedience—not the reason we abandon the command.

5. Unity does not mean agreeing about everything

This is particularly important when dealing with controversial issues such as Bible translations, textual criticism, church traditions, and secondary theological questions.

Biblical unity does not mean:

"Everyone must agree with me on every theological question."

Romans 14 provides an important example. Paul recognizes differences among Christians concerning disputable matters while commanding believers not to despise or condemn one another.

Likewise, Philippians 3:15 says:

"And if in any thing ye be otherwise minded, God shall reveal even this unto you."

There can be differences without immediately turning those differences into separation.

Of course, this does not mean doctrine is unimportant. The church must contend for the apostolic faith. Paul strongly warns against false gospels and serious doctrinal error.

But we must distinguish between:

essential gospel truth,

important doctrine,

and

secondary or disputable matters.

If every disagreement becomes a test of Christian fellowship, the church will continually fragment.

6. Unity and truth belong together

Biblical unity is not "peace at any price."

Jesus prayed:

"Sanctify them through thy truth: thy word is truth."
— John 17:17

Then:

"that they all may be one."
— John 17:21

So biblical unity is unity in truth, not unity through abandoning truth.

Ephesians 4 brings the two together beautifully:

"speaking the truth in love"

Truth without love can become harsh and divisive.

Love without truth becomes doctrinally empty.

The church needs truth AND love.

7. The church is called to show the world what reconciliation looks like

Ephesians 2 is especially powerful here.

Christ did not merely save individual Jews and individual Gentiles separately. He created one new humanity.

That means the church itself is supposed to be a demonstration of the reconciling power of the gospel.

If the church says:

"We are sinners, therefore we cannot live in unity,"

the world can reasonably ask:

What difference has the reconciliation of Christ actually made?

But when Christians with different backgrounds, cultures, personalities, social positions, and even secondary theological differences genuinely love one another and remain together in Christ, the church becomes a living testimony to the gospel.

8. What is the church's call?

The call is not:

"Wait for Christ to make us one."

The call is:

"Live as the one body Christ has already made us."

Paul's practical instructions are remarkably clear:

"With all lowliness and meekness, with longsuffering, forbearing one another in love; endeavouring to keep the unity of the Spirit in the bond of peace."
— Ephesians 4:2–3

And Jesus says:

"By this shall all men know that ye are my disciples, if ye have love one to another."
— John 13:35

So the church's responsibility is to pursue unity, protect unity, repair unity when it is damaged, and refuse unnecessary division.

A theological correction to the statement

I would therefore reformulate the statement this way:

"Because of our sinful nature, the earthly church will never experience perfect and complete unity before Christ returns. Nevertheless, Christ has already made His church one, and Scripture commands us to preserve and demonstrate that unity now through humility, love, truth, forgiveness, patience, and mutual submission."

That is much closer to the New Testament.

And there is a particularly important lesson here for church controversies: our sinfulness should make us more humble about our own judgments, more patient with fellow Christians, and more determined to preserve the unity Christ has given us—not more willing to divide the body of Christ.

Paul's command remains:

"Endeavouring to keep the unity of the Spirit in the bond of peace."
— Ephesians 4:3

The church does not have to wait until heaven to obey that command.