John 17:11-24 (AMP)
11 And [now] I am no more in the world, but these are [still] in the world, and I am coming to You. Holy Father, keep in Your Name [in the knowledge of Yourself] those whom You have given Me, that they may be one as We [are one].
12 While I was with them, I kept and preserved them in Your Name [in the knowledge and worship of You]. Those You have given Me I guarded and protected, and not one of them has perished or is lost except the son of perdition [Judas Iscariot—the one who is now doomed to destruction, destined to be lost], that the Scripture might be fulfilled.
13 And now I am coming to You; I say these things while I am still in the world, so that My joy may be made full and complete and perfect in them [that they may experience My delight fulfilled in them, that My enjoyment may be perfected in their own souls, that they may have My gladness within them, filling their hearts].
14 I have given and delivered to them Your word (message) and the world has hated them, because they are not of the world [do not belong to the world], just as I am not of the world.
15 I do not ask that You will take them out of the world, but that You will keep and protect them from the evil one.
16 They are not of the world (worldly, belonging to the world), [just] as I am not of the world.
17 Sanctify them [purify, consecrate, separate them for Yourself, make them holy] by the Truth; Your Word is Truth.
18 Just as You sent Me into the world, I also have sent them into the world.
19 And so for their sake and on their behalf I sanctify (dedicate, consecrate) Myself, that they also may be sanctified (dedicated, consecrated, made holy) in the Truth.
20 Neither for these alone do I pray [it is not for their sake only that I make this request], but also for all those who will ever come to believe in (trust in, cling to, rely on) Me through their word and teaching,
21 That they all may be one, [just] as You, Father, are in Me and I in You, that they also may be one in Us, so that the world may believe and be convinced that You have sent Me.
22 I have given to them the glory and honor which You have given Me, that they may be one [even] as We are one:
23 I in them and You in Me, in order that they may become one and perfectly united, that the world may know and [definitely] recognize that You sent Me and that You have loved them [even] as You have loved Me.
24 Father, I desire that they also whom You have entrusted to Me [as Your gift to Me] may be with Me where I am, so that they may see My glory, which You have given Me [Your love gift to Me]; for You loved Me before the foundation of the world.

Unity is important and expected of all Christian as was very important to Christ which made it a major theme in the His mind as He faced His death and I believe it should be of paramount importance to us all. The success of the message of the gospel is dependent on us working as one according to Philippians 2:2.
Unity is an integral part of any group, organisation and faith, life generally functions better with unity in the mix. According to Psalm 133:1, unity is, a good and a pleasant thing; and especially among brethren—members of the same family, of the same Christian community, and the same nation. And why not among the great family of mankind?
Nimrud in genesis 11 knew something a lot of believers have yet to catch onto- “united” we can do more than on our own.
Paul addressed the strife, contentions and quarrels among the Corinth believers and encouraged them to work in unity actively and progressively, 1 Corinthians 1:10. But how do we achieve what Paul is talking about in the text?
That they all may be one. The centre of unity is not on earth but in heaven. Christians are ‘one,’ because they are spiritually united to the Father and the Son, whose divine life and blessed union they share through the faith that gives eternal life through john 3:16. In its deepest sense, the unity of the Church cannot and should not be broken by outward divisions, whilst inward unity ought also to show itself in visible outward unity, “that the world may know that Thou hast sent Me.” Hence every Christian is bound to pray and work for the reunion of Christendom.
Looking at what Jesus said in vs 22-23 we begin to understand that unity is Spirit-rooted, Christ-centred and manifested, and truth-cherishing. Humbly loving unity is designed by God to meet two goals: to be a witness to the world, and acclamation of the glory of God, unity is made perfect only in Christ and a process just as any fruit of the Spirit. Every Christian should be progressively filled with the spirit of unity.
The ultimate aim of Christian unity is the glory of God. Hence Paul prays, “May the God of endurance and encouragement grant you to live in such harmony with one another, in accord with Christ Jesus, that together you may with one voice glorify God and Father of our Lord Jesus Christ. Therefore welcome one another as Christ has welcomed you, for the glory of God” Romans 15:5–7.
How can we advocate and encourage unity? Although we are all different, we have one spirit, one Lord—Jesus Christ, one faith—One system of religion, one baptism —Administered in the name of God the Father.
There are so many examples of unity in the Bible, Paul wrote about unity a lot, imploring churches to pursue unity and praying that they would seek that unification in Christ.
I encourage us, as desperately as I feel to seek unity wherever we are.
Be of one mind. Unity of mind. United in the same mind.
United in thinking, united in goals, united in priorities. United in and by Christ.
Shalom