Then why does Jesus pray for all those who believe in Him?
St. John 17: 6-21
6 I have manifested thy name to the men whom thou hast given me out of the world. Thine they were, and to me thou gavest them; and they have kept thy word. 7 Now they have known, that all things which thou hast given me, are from thee: 8 Because the words which thou gavest me, I have given to them; and they have received them, and have known in very deed that I came out from thee, and they have believed that thou didst send me. 9 I pray for them: I pray not for the world, but for them whom thou hast given me: because they are thine: 10 And all my things are thine, and thine are mine; and I am glorified in them.
11 And now I am not in the world, and these are in the world, and I come to thee. Holy Father, keep them in thy name whom thou has given me; that they may be one, as we also are. 12 While I was with them, I kept them in thy name. Those whom thou gavest me have I kept; and none of them is lost, but the son of perdition, that the scripture may be fulfilled. 13 And now I come to thee; and these things I speak in the world, that they may have my joy filled in themselves. 14 I have given them thy word, and the world hath hated them, because they are not of the world; as I also am not of the world. 15 I pray not that thou shouldst take them out of the world, but that thou shouldst keep them from evil.
16 They are not of the world, as I also am not of the world. 17 Sanctify them in truth. Thy word is truth. 18 As thou hast sent me into the world, I also have sent them into the world. 19 And for them do I sanctify myself, that they also may be sanctified in truth.
20 And not for them only do I pray, but for them also who through their word shall believe in me; 21 That they all may be one, as thou, Father, in me, and I in thee; that they also may be one in us; that the world may believe that thou hast sent me. 22 And the glory which thou hast given me, I have given to them; that they may be one, as we also are one:
Jesus is not praying for all those who believe in Him...for even the devils believe and tremble...St.James 2:19. And Jesus certainly never prayed for the Devil.
So, get "All those who believe" out of mind for these passages in St.John 17 6-21 specify those for whom Our Lord is praying and why.
In vs. 6-19, we read that Jesus is praying specifically for the Apostles, v. 11 that they may be one, that is, unified in the one Spirit, that they all preeach the same Gospel,...why is He praying for them? Becasue Jesus is getting ready to send them out to continue His mission... that is, to teach and baptize all nations in His Name. St.Matt. 28:16-20. He asks God to sanctify them in the truth...and it follows there is only One Spirit, One God, there is only one truth...Jesus wants His Apostles "all on the same page" so to speak regarding all that He had taught and shown them.
In v. 20, Jesus, after praying for His Apostles, then prays also for those who after hearing the Apostles' teach and preach the Good News are converted to the Faith (become believers).
You ask WHY does Jesus pray for the believers....the answer is found in v. 21...that they may be one, just as Jesus and the Father are One.
Unity is not mentioned, he prays for all believers!
Yes, Christ prays that those who believe in Him are unified....His prayer that they may be one is mentioned 4 times at the end.
Eph. 4:4-5 explains what that unity is ..... One Shepherd, one flock, one Faith, etc.....
So, let's look at the whole thing:
1As a prisoner for the Lord, then, I urge you to live a life worthy of the calling you have received. 2Be completely humble and gentle; be patient, bearing with one another in love. 3Make every effort to keep the unity of the Spirit through the bond of peace. 4There is one body and one Spirit—just as you were called to one hope when you were called— 5one Lord, one faith, one baptism; 6one God and Father of all, who is over all and through all and in all.
First, in St.John 17, we learn specifically WHO Jesus prays for....His Apostles those whom they bring to the Faith.
Second, we learn WHY Jesus prayed for them...that they might all be one, as per Eph. 4:3, that they "Make every effort to keep the unity of the Spirit through the bond of peace."
Third, Ephesians 4:1-6 confirms WHAT they might be unified in...."One Lord, one Faith, one Baptism, One God and Father of all, who is over all and through all and in all."
"Make every effort to keep the unity of the Spirit", not of the Church. "one God and Father of all, who is over all and through all and in all." seems to me that includes everyone (your all word you were looking for). Here's another passage on unity.
Before Christ ascended into Heaven, He promised the power of the Holy Spirit would be given to the Infant Chruch just before they would be sent out to teach all nations. Acts. 1:8. Ten days later on the First Pentecost Day the Apostles and disciples recived the Holy Spirit in tongues of fire.
You have asked on another thread that I might show you how Scripture shows that Christ established a Church that is the Catholic Church of today.
One of the titles of the Church is “the Bride of Christ.” No institution was ever joined so closely to one Man as the Church is with her Founder.” Like Him, she has the universal mission to teach all men and guide them to their eternal destiny.
First, Christ predicted the advent of His Church saying, “I must preach the kingdom of God, for therefore am I sent.” St.Luke 4:43. He called the Apostles and appointed them as teachers and rulers in His Church. “Teach men to observe all things whosoever I have commanded you. Behold I am with you all days even to the end of the world.” St.Matt.28:20. He constituted St.Peter as head, “thou art Peter and upon this rock I will build my Church." St. Peter could not have been the rock-foundation of Christ’s Church unless he was given authority to teach and rule. This authority was promised in the words “I will give to thee the keys to the Kingdom of Heaven.” The kingdom was to be a visible kingdom as a city set on a hill. Christ taught and trained them not for their benefit only, but that they might be teachers of others. They were the seed of the Church.
When Christ warned this little society unto themselves about their obligation of correcting the brethren, He said, “If he (the erring one) refuses to hear them, appeal to the Church, but if he refuses to hear even the Church, let him be to thee as the heathen and the publican. Amen, I say to you, whatever you bind on earth, shall be bound also in Heaven and whatever you loose on earth, shall be loosed in Heaven.” St.Matt. 18: 17-18. The spiritual power of the Apostles had extended to loosing and binding…”Whose sins you shall forgive, they are forgiven, and those sins you shall retain, they are retained." St.John 20:23. In these words of commission, the distinctive marks of the Catholic Church already stand out. Man’s relations with God are not left to the individual, but are under the control of authority. This authority was established by the will of God and those who hold it are not all men, but only a few, namely the Apostles. And since the Apostles could not live forever, this authority was to descend to their successors.
Here is the first mention of the word “Church” in the NT, a word that means an assembly and in the OT was applied to the entire people of God. Christ intended the Church to be the new Israel whose authority was to endure forever.
Christ was crucified and rose from the dead. Before He ascended into Heaven, He commanded them to go and make disciples of all nations, baptizing them, teaching them to observe ALL that he had commanded telling them He would be with them all days until the end of the world. He conferred on St.Peter the power that He had promised. “Feed My sheep. Feed My lambs.” Through this preaching and hearing of the Word, and its acceptance by the nations, the Kingdom of God was to be established, developed and perpetuated.
The Lord ascended into Heaven and for a time His initial group of followers remained in Jerusalem awaiting the event Christ said would take place. On Pentecost Day, the Holy Spirit came upon them in what Acts 2:3 calls “tongues of fire”. After Pentecost the Apostles acted collectively as officers of the newly formed religious society. Throughout Acts we read how they exercised their God-given authority to teach, govern and sanctify. Over both Jewish and Gentile converts, their authority was accepted as from the divine, and they claimed such 1Cor. 2:1-5; or in judging 1Cor. 5 or in rebuking, 1Cor. 6, or in making laws or giving precepts 1Cor. 11, 12 and 14.
Under the Apostles inferior ministers already began called deacons and presbyters and bishops, who together with the Apostles formed a true hierarchy. 1St.Peter 2:9, 12, 25; 5. St.Paul through "the laying on of hands" ordained the fullness of the priesthood upon Timothy and Titus whom he sent to organize churches.
Christ said I will be with My Church all days until the end of the world. Now the only Church that has been all days in the world since Christ is the Catholic Church and if He did not establish that Church, He established none. If that Church failed, then the gates of Hell have prevailed against Christ's Church and He has not been with her all days since His time until now. The Catholic Church alone has the essential constitution prescribed by Christ and alone behaves as possessing the magisterial, sanctifying (7 Sacraments) and diciplinary authority He conferred upon His Church as per the Gospel accounts. Yes, now there are external differences insofar as the grown tree differs from the seed, but the development is in full accordance with the nature and principle of the seed. And Christ knew that just a tree as the Catholic Church is today would develop from the seed He planted.