Paul was among the believing remnant of Israel.
Are you saying that he wasn't in the Body of Christ?
No. He was not.
He was saved after God concluded Unbelieving Israel as having continued in the Uncircumcision of their hearts; Acts 7; Romans 2 and 3 and 11.
When he was saved, he was in Unbelief or Uncircumcision.
His point in Romans 11 is that, although Unbelieving Israel has been concluded in Unbelief; God is not through with Israel. That it only looked as if God was through with Israel.
In this, Paul was not only the first member of God's New Creature this side of Israel's fall, and temporary setting aside, but his salvation when he was in Unbelief, typifies Israel's future salvation when they too will look at Him Who they pierced, while in Unbelief.
At which point, theirs will also be Paul's shock that Jesus was the Christ.
This had been Paul's shocking experience of Israel's Messiah while he was yet in the Uncircumcision of his heart - the shock of Paul's experience of Israel's Messiah, as one born out of, or before his nation's due time salvation...
Acts 26:6 And now I stand and am judged for the hope of the promise made of God unto our fathers: 26:7 Unto which promise our twelve tribes, instantly serving God day and night, hope to come. For which hope's sake, king Agrippa, I am accused of the Jews. 26:8 Why should it be thought a thing incredible with you, that God should raise the dead? 26:9 I verily thought with myself, that I ought to do many things contrary to the name of Jesus of Nazareth. 26:10 Which thing I also did in Jerusalem: and many of the saints did I shut up in prison, having received authority from the chief priests; and when they were put to death, I gave my voice against them. 26:11 And I punished them oft in every synagogue, and compelled them to blaspheme; and being exceedingly mad against them, I persecuted them even unto strange cities. 26:12 Whereupon as I went to Damascus with authority and commission from the chief priests, 26:13 At midday, O king, I saw in the way a light from heaven, above the brightness of the sun, shining round about me and them which journeyed with me. 26:14 And when we were all fallen to the earth, I heard a voice speaking unto me, and saying in the Hebrew tongue, Saul, Saul, why persecutest thou me? it is hard for thee to kick against the pricks. 26:15 And I said, Who art thou, Lord? And he said, I am Jesus whom thou persecutest.
This will be his nation's shocking encounter with said Messiah - their realization they have been in the Uncircumcision of their hearts...
Their shock when they see face to face Who has delivered them - Jesus of Nazareth...
Zechariah 12:1 The burden of the word of the LORD for Israel, saith the LORD, which stretcheth forth the heavens, and layeth the foundation of the earth, and formeth the spirit of man within him. 12:2 Behold, I will make Jerusalem a cup of trembling unto all the people round about, when they shall be in the siege both against Judah and against Jerusalem. 12:3 And in that day will I make Jerusalem a burdensome stone for all people: all that burden themselves with it shall be cut in pieces, though all the people of the earth be gathered together against it. 12:4 In that day, saith the LORD, I will smite every horse with astonishment, and his rider with madness: and I will open mine eyes upon the house of Judah, and will smite every horse of the people with blindness. 12:5 And the governors of Judah shall say in their heart, The inhabitants of Jerusalem shall be my strength in the LORD of hosts their God. 12:6 In that day will I make the governors of Judah like an hearth of fire among the wood, and like a torch of fire in a sheaf; and they shall devour all the people round about, on the right hand and on the left: and Jerusalem shall be inhabited again in her own place, even in Jerusalem. 12:7 The LORD also shall save the tents of Judah first, that the glory of the house of David and the glory of the inhabitants of Jerusalem do not magnify themselves against Judah. 12:8 In that day shall the LORD defend the inhabitants of Jerusalem; and he that is feeble among them at that day shall be as David; and the house of David shall be as God, as the angel of the LORD before them. 12:9 And it shall come to pass in that day, that I will seek to destroy all the nations that come against Jerusalem. 12:10 And I will pour upon the house of David, and upon the inhabitants of Jerusalem, the spirit of grace and of supplications: and they shall look upon me whom they have pierced, and they shall mourn for him, as one mourneth for his only son, and shall be in bitterness for him, as one that is in bitterness for his firstborn. 12:11 In that day shall there be a great mourning in Jerusalem, as the mourning of Hadadrimmon in the valley of Megiddon. 12:12 And the land shall mourn, every family apart; the family of the house of David apart, and their wives apart; the family of the house of Nathan apart, and their wives apart; 12:13 The family of the house of Levi apart, and their wives apart; the family of Shimei apart, and their wives apart; 12:14 All the families that remain, every family apart, and their wives apart.
He was not of the Believing Remnant.
Nor could he be - for He had blasphemed the Spirit, Matt. 10:30-32.