“Neither pray I for these alone, but for them also which shall believe on Me through their word” (John 17:20).
Most Bible commentaries maintain that the Lord was talking about you and me, and all of the other members of the Body of Christ who had not yet believed on Him at that time. The problem with this view is that you and I didn’t believe on Christ through the words of the twelve apostles. We believed on Him through the words of the Apostle Paul! Paul is the only biblical writer who presents salvation by grace through faith in the blood of the Lord Jesus Christ (Rom. 3:25). If someone introduced you to Christ using the words of the twelve apostles, they had to read Paul’s gospel into their words, for he is the only biblical writer to preach the death, burial, and resurrection of Christ as the gospel that must be believed in order to be saved (I Cor. 15:1-4).
So who were those who were saved through the word of the apostles? Well, the twelve preached their word at Pentecost, which tells us that those who believed through their word were all Jews, for they were the only people that Peter addressed on that day (Acts 2:14,22,36). So in praying for “them also which shall believe through their word,” the Lord was praying for future Jewish believers. Of course, this means that He had only Jewish believers in mind when He went on to pray for these future saints.
“That they all may be one…that the world may believe that Thou hast sent Me” (John 17:21).
Here again, the commentaries all contend that the Lord was talking about us. After all, didn’t Paul say of Christ, “He is our peace, who hath made both one” (Eph. 2:14), speaking of how Jews and Gentiles were all “baptized into one body” (I Cor. 12:13). The commentaries insist that this is what the Lord had in mind when He prayed “that they all may be one.”
But we’ve already seen that this couldn’t be what the Lord had in mind, since those who believed on Him through the word of the apostles were all Jews. So why was He praying that the Jews might be made one?
Well, if you know your Bible, you know that there came a time in Israel’s history when the ten northern tribes broke away from the two southern tribes and formed their own kingdom (I Kings 12). While God allowed this, He had no intention of letting His people be divided forever! To illustrate this, God instructed Ezekiel to take a stick and write “Israel” on it to represent the ten northern tribes, and then to take another stick and write “Judah” on it to represent the two southern tribes, then to join them together and “make them one stick” (Ezek. 37:15-19). He was told to do all this to illustrate God’s plan to take Israel and Judah and “make them one nation” (Ezek. 37:22). This, then, is the oneness for which the Lord prayed in our text.
Was His prayer answered? You know it was! At Pentecost, “there were dwelling at Jerusalem Jews…out of every nation under heaven” (Acts 2:5). “And all that believed…were together…continuing daily with one accord…with…singleness of heart” (Acts 2:41-46).
Of course, the Lord had a purpose in mind for praying for the reunion of Israel’s two houses. It was, as He said, “that the world may believe that Thou hast sent Me”; and when the reuniting of Israel’s two houses continues in the millennial kingdom, their oneness will cause the world to believe on Christ.
Do you think this will work today? That is, when the world sees the oneness that we have in Christ, do you think maybe they might want in on it? I know for sure that it works the other way! When we bite and devour one another, the world about us finds this most UNattractive. Brethren, do you know who does the most to keep people from believing on Christ? It is not murderers, rapists, and thieves; nothing that men like that do keeps men from believing. No, it is Christians who can’t get along with one another, and who present a poor testimony to the world in other ways, that keep men from believing on Christ. Why not determine right now that as a Christian you are going to “walk worthy of this calling…that the name of our Lord Jesus Christ may be glorified in you” (II Thes. 1:11,12). source