Introduction

We have been going through the fourth chapter of Ephesians. Let’s review. After three chapters extolling the blessings of God shown to believers in Christ Jesus, Paul begins to address how we live in response to those blessings. In verse 1 he tells us to walk in a manner worthy of the blessed calling we have received. Verses 2 and 3 lay out the manner of that walk. It is to be done in humility and gentleness, with patience and bearing with one another in love. It is to be accompanied by an eagerness to maintain unity of the Spirit in the bond of peace.

With the term “unity” Paul has introduced the central idea in the passage of verses 1-16. He then, in verses 4 through 6, presents the elements upon which unity is founded – one body, one Spirit, one hope, one Lord, one faith, one baptism, and one God and Father. These are foundational truths that cannot be changed by us.

Nevertheless, we have a role to play in manifesting unity. We have been given grace from Christ who distributes gifts to his people. We all have the necessary gifts and power to contribute. Furthermore, Christ has given to the church offices – apostles and prophets who laid the foundation, then evangelists to spread the gospel and start churches, then pastors-teachers who shepherd those churches. These different types of teachers equip us to work together in building the body of Christ.

Now, here is the question – What for? What are we building? What is our unity to be achieving? This is what verses 13 and 14 address.

Text

Read verse 13:

until we all attain to the unity of the faith and of the knowledge of the Son of God, to mature manhood, to the measure of the stature of the fullness of Christ,

Our unity is to be achieving unity – to the unity of the faith and of the knowledge of the Son of God. The goal is not merely to agree with one another, but to agree on “the faith,” that is, the gospel, and on the Son of God, Jesus Christ. It is critical what we are united about. For if we grow together in the right understanding of the faith and of the knowledge of the Son of God, we will attain maturity, indeed we will grow to “the measure of the stature of the fullness of Christ.” To put it simply, we will become like Christ; we will grow into his image. That is where we are trying to get; that is where our walk is to take us, both as individuals and as a united church.

The opposite of maturity is remaining as a child, as described in verse 14:

so that we may no longer be children, tossed to and fro by the waves and carried about by every wind of doctrine, by human cunning, by craftiness in deceitful schemes.

Being like a child is not always bad. Jesus wants us to have the humility of a child. Indeed, the only way to enter the kingdom of God is through such humility. But remaining like a child in the way that we receive and assimilate knowledge is not healthy. Just as we want our children to develop mentally and to build on knowledge, so we are to develop spiritually. Otherwise, we will not only fail to progress, but will become unstable as we go from one way of thinking to the next based on the skill of others to manipulate us.

To understand more clearly what Paul is saying in these verses, we are going to look at two childish churches as case studies, both of whom were started by Paul himself. That fact alone should alert us that falling away from “unity of the faith” can happen to any church. The churches are the church in Corinth and the church in Galatia.

Paul wrote to the Corinth church: “But I, brothers, could not address you as spiritual people, but as people of the flesh, as infants in Christ. I fed you with milk, not solid food, for you were not ready for it. And even now you are not yet ready, for you are still of the flesh” (1 Corinthians 3:1-3).

What was wrong with the church? He goes on to say there is jealousy and strife among them. That strife rose from doctrinal error. The church was filled with people who thought they had arrived spiritually, indeed, even passing Paul himself. They had gotten caught up in two things – their spiritual gifts and their freedom in Christ. Their gifts led them to believe they were wiser than they were. They thought they were extra spiritual, when in reality they were merely mimicking the world in wanting to be looked up to as special. As to the concept of freedom in Christ, they loved the concept so much that it led them to be “free” to act just like the world in their morals. The result was a church indistinguishable from their neighbors, except for having the added conceit of portraying themselves as being God’s favored people.

The Galatia church (or rather, the churches in the territory of Galatia) went a different direction. They did not think they were good enough. That is what the teachers, who followed Paul and known as Judaizers, taught them. Faith in Christ was not enough to be saved. These Gentile Christians had to also, in essence, become Jews. They needed to follow the Jewish laws, including for the men to be circumcised. The result was a legalistic church, in which following the law was what mattered.

These churches, though they had received as solid a foundation as possible under the Apostle Paul, had remained as children, shifting with whatever teaching deluded them. And in each case, though they went in decidedly opposite directions, the same fundamental errors tripped them up. Those errors were departing from the essentials of the faith, the gospel, rather than building upon the essentials, and, most critically, faltering in their knowledge of Jesus Christ, the Son of God.

The Corinth church, wowed by the gifts of the Spirit, lost interest in the cross of Christ. Indeed, it became an embarrassment for them. They grew tired of Paul because he wouldn’t leave the subject alone. They wanted to hear more about being spiritual. The Holy Spirit – now that was what they had ears for, not understanding that the role of the Spirit is to turn our attention to Christ. Maybe the work of Christ on the cross was an important teaching for beginners, but one needed to move on to higher knowledge and not be encumbered, by the way, with old morals.

The Galatian churches saw the cross also as a mere entry doctrine. What Jesus did on the cross made access to God possible, but, as these Judaizers explained, it wasn’t enough to go all the way in being accepted by God. They needed to do their part to earn acceptance.

But the cross, what Jesus Christ did on the cross, is what matters! And not simply as an entry point into the new life but as the central, guiding work and principle that informs everything else we believe and do. We don’t pass on from it; we build upon it; we receive every other teaching, every other bit of knowledge through its prism.

Listen to Paul teach this to each church. To the Corinth church:

For Christ did not send me to baptize but to preach the gospel, and not with words of eloquent wisdom, lest the cross of Christ be emptied of its power.

 For the word of the cross is folly to those who are perishing, but to us who are being saved it is the power of God (1 Corinthians 1:17-18).

And I, when I came to you, brothers, did not come proclaiming to you the testimony of God with lofty speech or wisdom. For I decided to know nothing among you except Jesus Christ and him crucified (2:1-2).

The wisdom that the mature recognize is the wisdom of God displayed on the cross. There we see how God could be “just and the justifier of the one who has faith in Jesus” (Romans 3:26). There on the cross is the foundational tenet upon which the gospel is laid and built. As Paul would later say to the Corinthians, here is the gospel: “that Christ died for our sins in accordance with the Scriptures, that he was buried, that he was raised on the third day in accordance with the Scriptures” (1 Corinthians 15:3-4). There is no burial and resurrection without the cross. There is no defeat of death, no deliverance from sin. There is no sending of the Holy Spirit to give all those neat spiritual gifts. There is no hope of arriving spiritually anywhere.

To the churches in Galatia Paul wrote:

I have been crucified with Christ. It is no longer I who live, but Christ who lives in me. And the life I now live in the flesh I live by faith in the Son of God, who loved me and gave himself for me. I do not nullify the grace of God, for if justification were through the law, then Christ died for no purpose (2:20-21).

Here Paul shows the essential place of the cross with anything in which we would place our hope. We cannot have grace without the cross. We cannot have justification without the cross. We cannot live for Christ without the cross. Without the cross everything else falls apart. There is no living for God. There is no winning acceptance. There is no other doctrine to hold on to if not grasped in the truth of the cross.

This is what unity in the faith is about – unity in holding onto the cross. Unity in the body of the crucified Christ; unity in the Spirit sent by the risen Lord who was victorious on the cross. We are baptized into the death of Jesus that we might be united with him in his resurrection. Our hope is to behold our Lord in glory and to join the heavenly choir as they worship the Lamb who was slain, who by being slain ransomed people for God from every tribe and language and people and nation.

And that is what unity in the knowledge of the Son of God is about – knowing Jesus Christ as the Lamb who made atonement for our sins. John the Baptist points him out, “Behold, the Lamb of God!” (John 1:36). Jesus says that he came “to give his life as a ransom for many” (Mark 10:45). That is how you must know him. Knowing him as friend is nice, but Jesus said that he came to lay down his life for his friends (John 15:13). Knowing him as prophet sent by God is okay, but this prophet identified himself as one with God, as he explained how he would lay down his life for his sheep (cf. John 10:14-30).

The Apostle Paul beheld the risen and ascended Lord Jesus Christ. Nevertheless, it was the crucified Lord on which he based his own hope for salvation. It was the crucified Lord that he determined to teach to his churches. And it was to be upon this central tenet – this foundation – that the churches and believers were to build.

So what happened? How did churches founded by the Apostle Paul himself go astray? Paul asks that question of the Galatians: “You were running well. Who hindered you from obeying the truth? (5:7) We know that teachers came in who led them astray, and it is not difficult to see how. As Christians they want to please God; they want to be obedient. They want to hear what God expects of them, and in come teachers from respected Judaism, the same tradition that their new faith is grounded in – these teachers instruct them on what a real God-honoring life is like, i.e. a life adhering to the law. This would be especially appealing to any Christian fearing that he might not be living a good enough life. The Corinthians – well, plain old pride got the best of them. They were enamored with their spiritual gifts which led them to conclude they were on some higher plane of spirituality. Whatever the reason, the great error for both was getting away from the core of the gospel, specifically losing focus on Jesus Christ.

Application

Let’s move to us, first as individuals. To apply the lesson to yourself, you must make a distinction between failing to live up to what you know and that of moving away from the gospel. Let me give an example.

Paul Tripp preaches in the evenings. In a typical sermon he will give either a penetrating diagnosis of heart sin or raise our eyes to the ideal of what we should be. Sometimes, he will make a comment like, “I wish I could say that I…” in brief, that he could live up to what he has preached. Now, however remorseful Dr. Tripp may be about his failures, he does not lose sleep at night over his salvation. He knows God loves him and accepts him. How does he know that? He tells us in his sermons. He points to Jesus Christ, to his work on the cross, to the grace and mercy of God displayed in Christ’s work. In other words, he takes us to the gospel.

As Christians, we do fail God. Sometimes, like the Corinthians, our pride gets the best of us; sometimes like the Galatians our fears trip us up. As Dr. Tripp would remind us, these are problems of the heart. But they need not be problems of the mind. They should not lead us away from what we know to be truth.

I have people come to see me who do keep the truth even as they are shaken. Some life experience has hit them hard – maybe an illness, troubles in a relationship, maybe a sin they have committed. They are fearful or angry. They are not sure they can handle the blow. But then, even as they express their troubles, they reveal they have not lost the gospel truth. They will say things like:

“I know God is in control…”

“I know Christ died for me…”

“I know I am saved by grace…”

Their trouble is in connecting the heart with the mind. That’s okay. That’s what we are always working on, and we grow in sanctification according to how deeply the gospel penetrates into our hearts. The real problem arises when we let the wavering heart re-instruct our minds. And we come to a conclusion like Christ’s work on the cross not being enough to save us, or that God really is not in control. It is the gospel truth that must inform our minds and hearts. It doesn’t work the other way around where we let our experiences and the responses of our hearts inform what we are to think. That is to be true for both individual and church.

I want to close with one more positive example for an individual and for a church on how keeping with gospel truth takes us through the hard times and keeps the heart, even as it struggles, on track.

On May 7, 2000, Dr. Boice stood in this pulpit for the last time to speak about his cancer that would take his life in a month. Here is an excerpt:

"If I were to reflect on what goes on theologically here, there are two things I would stress. One is the sovereignty of God. That’s not novel. We have talked about the sovereignty of God here forever. God is in charge. When things like this come into our lives, they are not accidental. It’s not as if God somehow forgot what was going on, and something bad slipped by. It’s not the answer that Harold Kushner gave in his book, Why Bad Things Happen to Good People. God does everything according to his will. We’ve always said that.

"But what I’ve been impressed with mostly is something in addition to that. It’s possible, isn’t it, to conceive of God as sovereign and yet indifferent? God’s in charge, but he doesn’t care. But it’s not that. God is not only the one who is in charge; God is also good. Everything he does is good. And what Romans 12:1-2 says is that we have the opportunity by the renewal of our minds—that is, how we think about these things—actually to prove what God’s will is. And then it says, “His good, pleasing, and perfect will.” Is that good, pleasing, and perfect to God? Yes, of course, but the point of it is that it’s good, pleasing, and perfect to us. If God does something in your life, would you change it? If you’d change it, you’d make it worse. It wouldn’t be as good. So that’s the way we want to accept it and move forward, and who knows what God will do?

“So that’s the way we want to accept it and move forward.” James Boice could accept what was happening because he knew the faith and he had the knowledge of the Son of God. And this church, as much as we might have struggled with our loss, could accept what was happening because we have been grounded in the faith and the knowledge of the Son of God. We know that God is sovereign. We know that God is good. We need only look to Jesus Christ to know that. And it is from that gospel truth that we are able to renew our minds and renew our hearts, whatever comes our way.

Whatever you are going through – however painful or troubling it may be – you will get through it. You will be all right. Indeed you will come out stronger as long as you keep the faith and look to Jesus Christ. And our church will be okay. We lost one beloved pastor to death; we have lost another because of God’s calling him to another service. But we will be okay as long as we keep to the unity of the faith and of the knowledge of the Son of God. Why, we will even mature, even grow toward the measure of the stature of the fullness of Christ. And that is the gospel truth.