"The mission" as you often rightly call THEIR mission, but then confuse the heck out of with the Apostle Paul's "mission" - was to their OWN...FIRST.
But they were also told they would not complete even that much within the cities of Israel BEFORE His return, Matt. 10:23.
The Twelve Tribes of Israel FIRST.
Which was to have gone on into THEIR Great Tribulation, rise of AntiChrist, and all the rest of that.
Followed by His return; gathering THEIR rest of said Twelve Tribes from the four corners of that then world.
And THEN THROUGH THEM - the Gentiles, Matt. 24.
But God had planned on temporarily stopping that; that He might reconcile BACK unto Himself - NOT the EARTH FIRST - BUT that EVEN NOW "spiritual wickedness in high (Heavenly) places" - the very destiny of His New Creature: The Body of Christ, Eph. 1; Col. 1.
Your huge, huge error decades ago was that you went in search of your answers in commentaries written by a school of thought that having failed to see this in Scripture; allegorized the heck out of much of it, in its' own conceit, Rom. 11.
The illogic of your views continuing from there to where you are now so ensnared by it after all these decades; that there is no longer much hope of you seeing these things as they are.
First this...
Matthew 24:6 And ye shall hear of wars and rumours of wars: see that ye be not troubled: for all these things must come to pass, but the end is not yet. 24:7 For nation shall rise against nation, and kingdom against kingdom: and there shall be famines, and pestilences, and earthquakes, in divers places. 24:8 All these are the beginning of sorrows. 24:9 Then shall they deliver you up to be afflicted, and shall kill you: and ye shall be hated of all nations for my name's sake. 24:10 And then shall many be offended, and shall betray one another, and shall hate one another. 24:11 And many false prophets shall rise, and shall deceive many. 24:12 And because iniquity shall abound, the love of many shall wax cold. 24:13 But he that shall endure unto the end, the same shall be saved.
Then this...
24:14 And this gospel of the kingdom shall be preached in all the world for a witness unto all nations; and then shall the end come.
But again - first this...
24:22 And except those days should be shortened, there should no flesh be saved: but for the elect's sake those days shall be shortened. 24:23 Then if any man shall say unto you, Lo, here is Christ, or there; believe it not. 24:24 For there shall arise false Christs, and false prophets, and shall shew great signs and wonders; insomuch that, if it were possible, they shall deceive the very elect. 24:25 Behold, I have told you before. 24:26 Wherefore if they shall say unto you, Behold, he is in the desert; go not forth: behold, he is in the secret chambers; believe it not. 24:27 For as the lightning cometh out of the east, and shineth even unto the west; so shall also the coming of the Son of man be. 24:28 For wheresoever the carcase is, there will the eagles be gathered together. 24:29 Immediately after the tribulation of those days shall the sun be darkened, and the moon shall not give her light, and the stars shall fall from heaven, and the powers of the heavens shall be shaken: 24:30 And then shall appear the sign of the Son of man in heaven: and then shall all the tribes of the earth mourn, and they shall see the Son of man coming in the clouds of heaven with power and great glory. 24:31 And he shall send his angels with a great sound of a trumpet, and they shall gather together his elect from the four winds, from one end of heaven to the other.
But first this...
Matthew 10:18 And ye shall be brought before governors and kings for my sake, for a testimony against them and the Gentiles. 10:19 But when they deliver you up, take no thought how or what ye shall speak: for it shall be given you in that same hour what ye shall speak. 10:20 For it is not ye that speak, but the Spirit of your Father which speaketh in you. 10:21 And the brother shall deliver up the brother to death, and the father the child: and the children shall rise up against their parents, and cause them to be put to death. 10:22 And ye shall be hated of all men for my name's sake: but he that endureth to the end shall be saved. 10:23 But when they persecute you in this city, flee ye into another: for verily I say unto you, Ye shall not have gone over the cities of Israel, till the Son of man be come.
Then this...
24:14 And this gospel of the kingdom shall be preached in all the world for a witness unto all nations; and then shall the end come.
Which per this, was delayed...
2 Peter 3:1 This second epistle, beloved, I now write unto you; in both which I stir up your pure minds by way of remembrance: 3:2 That ye may be mindful of the words which were spoken before by the holy prophets, and of the commandment of us the apostles of the Lord and Saviour: 3:3 Knowing this first, that there shall come in the last days scoffers, walking after their own lusts, 3:4 And saying, Where is the promise of his coming? for since the fathers fell asleep, all things continue as they were from the beginning of the creation.
3:8 But, beloved, be not ignorant of this one thing, that one day is with the Lord as a thousand years, and a thousand years as one day. 3:9 The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance. 3:10 But the day of the Lord will come as a thief in the night; in the which the heavens shall pass away with a great noise, and the elements shall melt with fervent heat, the earth also and the works that are therein shall be burned up. 3:11 Seeing then that all these things shall be dissolved, what manner of persons ought ye to be in all holy conversation and godliness, 3:12 Looking for and hasting unto the coming of the day of God, wherein the heavens being on fire shall be dissolved, and the elements shall melt with fervent heat? 3:13 Nevertheless we, according to his promise, look for new heavens and a new earth, wherein dwelleth righteousness. 3:14 Wherefore, beloved, seeing that ye look for such things, be diligent that ye may be found of him in peace, without spot, and blameless. 3:15 And account that the longsuffering of our Lord is salvation; even as our beloved brother Paul also according to the wisdom given unto him hath written unto you; 3:16 As also in all his epistles, speaking in them of these things; in which are some things hard to be understood, which they that are unlearned and unstable wrest, as they do also the other scriptures, unto their own destruction.
Even as our beloved brother Paul had written unto them?
That is not in Hebrews.
Where it is found is in...
Romans 9:6 Not as though the word of God hath taken none effect. For they are not all Israel, which are of Israel: 9:7 Neither, because they are the seed of Abraham, are they all children: but, In Isaac shall thy seed be called.
9:19 Thou wilt say then unto me, Why doth he yet find fault? For who hath resisted his will? 9:20 Nay but, O man, who art thou that repliest against God? Shall the thing formed say to him that formed it, Why hast thou made me thus? 9:21 Hath not the potter power over the clay, of the same lump to make one vessel unto honour, and another unto dishonour? 9:22 What if God, willing to shew his wrath, and to make his power known, endured with much longsuffering the vessels of wrath fitted to destruction: 9:23 And that he might make known the riches of his glory on the vessels of mercy, which he had afore prepared unto glory, 9:24 Even us, whom he hath called, not of the Jews only, but also of the Gentiles?
9:30 What shall we say then? That the Gentiles, which followed not after righteousness, have attained to righteousness, even the righteousness which is of faith. 9:31 But Israel, which followed after the law of righteousness, hath not attained to the law of righteousness. 9:32 Wherefore? Because they sought it not by faith, but as it were by the works of the law. For they stumbled at that stumblingstone; 9:33 As it is written, Behold, I lay in Sion a stumblingstone and rock of offence: and whosoever believeth on him shall not be ashamed.
Romans 11:1 I say then, Hath God cast away his people? God forbid. For I also am an Israelite, of the seed of Abraham, of the tribe of Benjamin. 11:2 God hath not cast away his people which he foreknew. Wot ye not what the scripture saith of Elias? how he maketh intercession to God against Israel, saying, 11:3 Lord, they have killed thy prophets, and digged down thine altars; and I am left alone, and they seek my life. 11:4 But what saith the answer of God unto him? I have reserved to myself seven thousand men, who have not bowed the knee to the image of Baal. 11:5 Even so then at this present time also there is a remnant according to the election of grace. 11:6 And if by grace, then is it no more of works: otherwise grace is no more grace. But if it be of works, then is it no more grace: otherwise work is no more work. 11:7 What then? Israel hath not obtained that which he seeketh for; but the election hath obtained it, and the rest were blinded.
11:11 I say then, Have they stumbled that they should fall? God forbid: but rather through their fall salvation is come unto the Gentiles, for to provoke them to jealousy. 11:12 Now if the fall of them be the riches of the world, and the diminishing of them the riches of the Gentiles; how much more their fulness? 11:13 For I speak to you Gentiles, inasmuch as I am the apostle of the Gentiles, I magnify mine office: 11:14 If by any means I may provoke to emulation them which are my flesh, and might save some of them. 11:15 For if the casting away of them be the reconciling of the world, what shall the receiving of them be, but life from the dead?
11:25 For I would not, brethren, that ye should be ignorant of this mystery, lest ye should be wise in your own conceits; that blindness in part is happened to Israel, until the fulness of the Gentiles be come in. 11:26 And so all Israel shall be saved: as it is written, There shall come out of Sion the Deliverer, and shall turn away ungodliness from Jacob: 11:27 For this is my covenant unto them, when I shall take away their sins. 11:28 As concerning the gospel, they are enemies for your sakes: but as touching the election, they are beloved for the fathers' sakes. 11:29 For the gifts and calling of God are without repentance. 11:30 For as ye in times past have not believed God, yet have now obtained mercy through their unbelief: 11:31 Even so have these also now not believed, that through your mercy they also may obtain mercy. 11:32 For God hath concluded them all in unbelief, that he might have mercy upon all.
There shall come out of Zion the Deliverer?
When?
Unto whom?
Isaiah 59:1 Behold, the LORD's hand is not shortened, that it cannot save; neither his ear heavy, that it cannot hear: 59:2 But your iniquities have separated between you and your God, and your sins have hid his face from you, that he will not hear. 59:3 For your hands are defiled with blood, and your fingers with iniquity; your lips have spoken lies, your tongue hath muttered perverseness. 59:4 None calleth for justice, nor any pleadeth for truth: they trust in vanity, and speak lies; they conceive mischief, and bring forth iniquity. 59:5 They hatch cockatrice' eggs, and weave the spider's web: he that eateth of their eggs dieth, and that which is crushed breaketh out into a viper. 59:6 Their webs shall not become garments, neither shall they cover themselves with their works: their works are works of iniquity, and the act of violence is in their hands. 59:7 Their feet run to evil, and they make haste to shed innocent blood: their thoughts are thoughts of iniquity; wasting and destruction are in their paths. 59:8 The way of peace they know not; and there is no judgment in their goings: they have made them crooked paths: whosoever goeth therein shall not know peace. 59:9 Therefore is judgment far from us, neither doth justice overtake us: we wait for light, but behold obscurity; for brightness, but we walk in darkness. 59:10 We grope for the wall like the blind, and we grope as if we had no eyes: we stumble at noon day as in the night; we are in desolate places as dead men. 59:11 We roar all like bears, and mourn sore like doves: we look for judgment, but there is none; for salvation, but it is far off from us. 59:12 For our transgressions are multiplied before thee, and our sins testify against us: for our transgressions are with us; and as for our iniquities, we know them; 59:13 In transgressing and lying against the LORD, and departing away from our God, speaking oppression and revolt, conceiving and uttering from the heart words of falsehood. 59:14 And judgment is turned away backward, and justice standeth afar off: for truth is fallen in the street, and equity cannot enter. 59:15 Yea, truth faileth; and he that departeth from evil maketh himself a prey: and the LORD saw it, and it displeased him that there was no judgment. 59:16 And he saw that there was no man, and wondered that there was no intercessor: therefore his arm brought salvation unto him; and his righteousness, it sustained him. 59:17 For he put on righteousness as a breastplate, and an helmet of salvation upon his head; and he put on the garments of vengeance for clothing, and was clad with zeal as a cloak. 59:18 According to their deeds, accordingly he will repay, fury to his adversaries, recompence to his enemies; to the islands he will repay recompence. 59:19 So shall they fear the name of the LORD from the west, and his glory from the rising of the sun. When the enemy shall come in like a flood, the Spirit of the LORD shall lift up a standard against him. 59:20 And the Redeemer shall come to Zion, and unto them that turn from transgression in Jacob, saith the LORD. 59:21 As for me, this is my covenant with them, saith the LORD; My spirit that is upon thee, and my words which I have put in thy mouth, shall not depart out of thy mouth, nor out of the mouth of thy seed, nor out of the mouth of thy seed's seed, saith the LORD, from henceforth and for ever.
Read it...believe it...as it is written.
Why?
2 Corinthians 4:13 We having the same spirit of faith, according as it is written, I believed, and therefore have I spoken; we also believe, and therefore speak; 4:14 Knowing that he which raised up the Lord Jesus shall raise up us also by Jesus, and shall present us with you.