The Nicene Creed states this about the church:
We believe in one holy catholic and apostolic Church.
In the Bible the church is the one worldwide fellowship of truly believing people whose head is Jesus Christ. It's holy because it's consecrated to God corporately, as each Christian is individually. It is catholic (not Roman Catholic but literally 'referring to the whole') because it embraces all true Christians everywhere and it is apostolic because it is founded on apostolic teaching and seeks to maintain the apostles' teaching and doctrine. So the Reformers said: The visible Church of Christ is an assembly of believing people in which the pure Word of God is preached and the Sacraments [baptism and the Lord's Supper] are ministered with due order and discipline as ordained by Christ. (From Article 19 of the Church of England.) And those four marks of the church can be seen clearly together in Ephesians 2:19-22. But also in Jesus' prayer for the church in John 17. He prays that the church may be united. But he also therefore prays that it would be apostolic and holy - 'sanctify them in the truth Jesus' prays in v17 - and catholic - 'so that the world may believe that the Father sent the Son' v21. And if we are to grow to be a church of 2000 over the next 5 years then we will need to be and grow to be one holy catholic and apostolic church. One in Spirit and purpose. One in the truth of the gospel. One in Christ by his power and prayer.
There's a story about a man who met someone about to jump off a bridge. He said: "Wait a minute, don't you believe in God?" The other person replied: "Yes, I do believe in God." "Really? Are you a Christian or a Jew?" "A Christian." "Me too. Are you a Protestant or a Catholic?" "I'm a Protestant." "Really? What denomination?" "Baptist." "Me too. Southern or Northern?" "Northern." "Northern Conservative Baptist or Northern Liberal Baptist?" "Northern Conservative Baptist." "Wow!” Me too. Northern Conservative Reformed Baptist or Northern Conservative Fundamentalist Baptist?" "Northern Conservative Fundamentalist Baptist." "Me too. This is amazing! Northern Conservative Fundamentalist Baptist Great Lakes Region or Northern Conservative Fundamentalist Baptist Eastern Region?" "Northern Conservative Fundamentalist Baptist Great Lakes Region." "Me too, this is incredible! Northern Conservative Fundamentalist Baptist Great Lakes Region Council of 1879 or Northern Conservative Fundamentalist Baptist Great Lakes Region Council of 1912?" He said: "Northern Conservative Fundamentalist Baptist Great Lakes Region Council of 1912." "What? You evil heretic!" and pushed him off the bridge.
Well in contrast to their division over secondary matters here's Paul writing to the church in Ephesus, chapter 4:2-3:
Walk with all humility and gentleness, with patience, bearing with one another in love, eager to maintain the unity of the Spirit in the bond of peace.(Ephesians 4:2-3)
What Paul's saying is this. If the Lord Jesus, by his Spirit, has brought me to faith in him and he’s also brought you to faith in him, then he’s created a unity and a bond between us that’s far deeper and longer-lasting than any other unity or bond - even marriage. So we're to be eager to work at relationships in this spiritual family. And that's an effort, because, applying this to ourselves, there are two major threats to the unity and peace of JPC. One is me. And the other is you. Because even though God is working on us and one day we'll be living perfectly under Jesus as Lord, right now we’re still full of our own, sinful egos. So we each have our view on what church should be like. We each have our convictions on secondary issues – and wish that everyone else would agree with us. We each have our frustrations with the way things are and with those who lead us. And Paul’s recipe for keeping the peace is in v2.
So, we're to ‘walk with all humility’. We need to learn to think not, ‘How would I like things to be’, but, ‘What would be best for everyone?’ Then, ‘walk with all gentleness’. The original means ‘not over-reacting’. Which assumes there will be things to react to – like people disappointing you or rubbing you up the wrong way, or sinning against you. And the church is going to be like that – it’s going to be far from perfect this side of heaven. So let's be gentle when giving criticism and when receiving criticism. And be patient bearing with one another in love. Then, v3: eager to maintain the unity of the Spirit in the bond of peace. Or, in the words from the marriage service, ‘What God has joined together, let man not separate.’ Because if we do split up into cliques within our church, or (more widely) if Christians split needlessly over secondary issues into lots of different churches, then the world will just look and say, ‘Well, they’re really no different from us – we can’t live together and nor can they.’ Well let's now turn to Jesus' prayer in John 17 where importantly we see 1st the basis of unity
1) The Basis of Unity
Usually by "Christian unity" people have in mind organizational unity. But that sort of unity isn't the main thrust of Jesus' concern here. In his prayer for Christians such as us, Jesus prays for unity with the Apostles. V20
“I do not ask for these only [the apostles], but also for those who will believe in me through their word, that they may all be one." (John 17:20-21)
This is the starting point of any concept of Christian unity. It's the common believing in the message of Jesus faithfully proclaimed by His Apostles that is the foundation. Only this can make for genuine Christian unity.
This is the first thing Jesus prays for Christians who would come after him; that as his church develops there would be continuity with the message of the Apostles. It is a oneness for those who "believe in me through their message" that Jesus asks his Father for. Real unity can only exist when what is believed by those who call themselves Christians is the good news of Jesus according to the Apostles which is their message available to us through the NT.
This is consistent with what Jesus has prayed for his Apostles themselves earlier in chapter 17. They are the model for what true believing is so, v8 , For I have given them the words that you gave me, and they have received them and have come to know in truth that I came from you; and they have believed that you sent me.
The major means to their unity, was loyalty to God's truth made known through Jesus. So again he prays to his Father for the Apostles v17 " Sanctify them (set them apart)in the truth; your word is truth." Commitment to the truth of God's word was Jesus' first prayerful concern for his church.
So "unity" at the expense of truth, is not Christian unity according to Jesus and not what he's praying for here. Sadly at all times in church history there have been those calling themselves "Christians" for whom those seeking to be loyal to the Bible have found it impossible to be at one.
Think of much of the medieval Catholic Church. There was a very real visible unity in that the whole of Western Europe had one institutional church - but the world did not believe the gospel. Because it was teaching falsehood people were led astray. It needed people, like Luther, to stand up for the gospel. The consequences of that stand, and loyalty to Jesus and his message as the Apostles had passed it on, were that institutional unity broke down, but true Christian unity, unity in the gospel was created and many truly believed in Jesus as a result.
Tragically the same is true today, unity is impossible with those who deny the truth of Jesus or who advocate behaviour at odds with God's word. Paul in 2Tim 2:17 likens false teaching to gangrene or cancer. Teaching and teachers who reject the truth of the Bible are like a cancer in the body of Christ. The church's unity cannot include them, or its life will be put in danger.
But being one in Christ's truth will bring with it a generous acceptance on matters of less importance that Christians disagree upon. For when the essential truths of the gospel are in common such minor differences don't prevent real Christian unity. I'm thankful to God that in this church this saying works in practice; "In necessary things; unity, in doubtful things; liberty, in all things charity."
It's also on that same foundation of unity in truth that churches can relate to other churches and we have links with other churches locally, nationally and internationally who are all seeking to stand in the truth of Jesus. Jesus then, prays that we would be one in his truth. Secondly he also gives
2) The Model of Unity
Jesus' prayer for unity has a pattern. It's not just that Christians being one is a nice idea; it is something that's rooted in the very nature of God himself.
Do you see the extraordinary implication of Jesus' prayer in v21? "I pray" says Jesus that they may all be one, just as you, Father, are in me, and I in you...
Christian unity, oneness between believers, is compared by Jesus to the kind of unity there is between God the Father and God the Son!
Jesus prays that his people would share in God's own relationships within the Godhead.
The glory that you have given me I have given to them, that they may be one even as we are one, I in them and you in me... (v22,23)
What Jesus has already taught the Apostles is that Jesus lives in his people by his Spirit; the "Spirit of truth" whom Jesus sends from the Father. As those who have been brought to faith in Jesus, Christians share in the perfect, loving, mutual relationships of God the Father, God the Son and God the Holy Spirit!
We share together in nothing less than the life of God Himself and we share together in nothing less than the love God enjoys within Himself! It's amazing! And there's something very important here as we consider Christian unity. As we saw earlier it means that there already is a spiritual unity between Christians. Unity exists now, it is a given. Formal organisations of Christians that may divide people structurally do not break this spiritual unity. Jesus' prayer has been and is being answered. We are one with God the Father through Jesus, an experience applied to us by the Holy Spirit. And as all Christians are indwelt by God's Spirit we are spiritually one in Jesus.
But Jesus prays for more v23 that they may become perfectly one...
Unity is something in which Christians must grow. Remember that Paul told the Ephesians to be eager to maintain the unity of the Spirit in the bond of peace. Oneness needs to be recognised and kept. Peace between believers needs to be maintained and lived out. To go back to Ephesians 4 there we're taught what a local church is to be like. Here is a community of believers from different backgrounds and with different temperaments and abilities but they are likened to the "body" of Jesus on earth. V4
There is one body and one Spirit—just as you were called to the one hope that belongs to your call— one Lord, one faith... [truth again is what unites them]. (Eph 4.4-5)
Each one of us has been given undeserved gifts from God (v7), so there is diversity in unity, to serve our fellow believers with whom we're linked. We're to grow together in love, we're to use our gifts for the good of the church which will lead to growth in every way. So this is important as we pray and plan towards being a church of 2000. Look at v15 ... speaking the truth in love, we are to grow up in every way into him who is the head, into Christ, from whom the whole body, joined and held together by every joint with which it is equipped, when each part is working properly, makes the body grow so that it builds itself up in love.
Now as we saw earlier things are not perfect in Ephesus as in this church, so we're to walk with all humility and gentleness, with patience, bearing with one another in love, which also means seeking to forgive those who have hurt us. As Jesus says back in John 15:12: love one another as I have loved you.
In what ways do you and I need to keep the unity of the Spirit at the moment? Are there things we need to do? People we need to speak to? Situations with other believers where we need to pray for strength to act in a way that keeps the peace?
In this broken world we need to keep being reminded of these realities and work hard to preserve the oneness we have been given. But the encouraging thing is that we can live in unity as believers in a manner you won't find anywhere else because we are people who are spiritually at one united in the truth of Jesus and united like God the Father and God the Son are united.
3) The Purpose of Unity
Jesus prays that Christians would be one in truth and spiritual life like he is one with his Father v21 ‘so that the world may believe that you have sent me.’
Jesus is saying that the oneness of his people will lead to people in the world believing in him. His truth will be communicated with words and by the lives of Christians united in church congregations. In this sense evangelism is a community act. It is the proclamation of the church's relationships as well as its convictions. The gospel proclaimed from the pulpit is either confirmed or contradicted by the quality of relationships in the pews.
Jesus prays, v23, ‘that they may become perfectly one, so that the world may know that you sent me and loved them even as you loved me.’
Jesus' prayer is that the love that God has for Jesus the Son is to be reproduced in relationships between Christians and this will show the world that Jesus is the God-man and rescuer he claims to be.
So people from different backgrounds sharing together, people facing difficulties who are comforted, lonely people who have found support, and practical loving action all illustrate the words of our lips and persuade the world to sit up and take notice.
And it's not just when we get it right that illustrates the gospel. How we deal with getting it wrong is important too. So the tolerance that is shown to people in the church family who do or say irritating things or the forgiveness which is offered when we've been hurt all because we know we belong to each other in Christ is like a powerful magnet drawing outsiders to Jesus. Lastly, but not least,
4) The Perfection of the Church's Unity is ensured by the Prayer of Jesus
Now there's a profound challenge to us in all of our lack of one-ness in these verses. But this is not primarily Jesus rebuking our failures and encouraging us to be one. This is a prayer. This is a window on to what the Son and the Father are cooking up together. Whatever Jesus asks from the Father, the Father gives him. When Jesus prays, it happens. In the end the unity of believers is God's work, not ours. And Jesus prays in v23: ‘I in them and you in me, that they may become perfectly one...’ Jesus didn't die in vain. His prayer is not refused. The church is one. The church is becoming one. The church will be one. Perfectly.