“Are THEY Hebrews? So am I. Are THEY Israelites? So am I. Are THEY Abraham’s descendants? So am I. Are THEY servants of Christ? ...I am more. I have worked much harder, been in prison more frequently, been flogged more severely, and been exposed to death again and again...” (2 Corinthians 11:22-27)
Who are the “THEY” that Paul is talking about?
It was the Jewish followers of Jesus who kept insisting that Gentiles cannot be saved without joining their group and obeying the Law of Moses. They were still clinging to some of the teaching of the "scribes and Pharisees, hypocrites"...who had rejected Jesus as the Christ/Messiah.
“…woe to you, scribes and Pharisees, hypocrites, because you shut off the kingdom of heaven from people; for you do not enter in yourselves, nor do you allow those who are entering to go in.” (Matthew 23:12-13)
This is still happening. Some teach that humanity must join the church or be eternally excluded from the Kingdom of God. But the good news/gospel message that comes from Jesus through the Apostle Paul says…."So then, just as one trespass brought condemnation for ALL HUMANITY, so also one act of righteousness brought justification and life for ALL HUMANITY. For just as through the disobedience of the one man (Adam) the many were made sinners, so also through the obedience of the one man (Jesus) the many will be made righteous. The law came in so that sins would increase; but where sin increased, grace increased all the more, so that, just as sin reigned in death, so also grace might reign through righteousness to bring eternal life through Jesus Christ our Lord." (Romans 5:18-21)
“…as in Adam ALL die, so also in Christ ALL will be made alive...” (1 Corinthians 15:22)
"This is a trustworthy saying, worthy of full acceptance.To this end we labor and strive, because we have set our hope on the living God, who is the Savior of everyone, and especially of those who believe. Command and teach these things." (1 Thessalonians 4:10-11)
Again, the salvation of sinners is not an offer to be accepted or an organization to be joined - it is good news to be believed and shared! Only a few humans seem to believe the good news in this life, yet ALL will believe after the resurrection and in joyful appreciation of their salvation…
“EVERY knee will bow, of those who are in heaven and on earth and under the earth, and EVERY tongue will confess that Jesus Christ is Lord, to the GLORY OF GOD the Father.” (Philippians 2:8-11)
"Blessed be the God and Father of our Lord Jesus Christ, who has blessed us with every spiritual blessing in the heavenly places in Christ, just as He chose us in Him before the foundation of the world, that we would be holy and blameless before Him. In love He PREDESTINED us to adoption as sons through Jesus Christ to Himself, according to the kind intention of HIS WILL, to the praise of the glory of HIS GRACE, which He FREELY BESTOWED ON US in the Beloved (Jesus). In Him we have redemption through HIS BLOOD, the forgiveness of our trespasses, according to the riches of His grace which He lavished on us. In all wisdom and insight He made known to us the secreet of His will, according to His kind intention which He purposed in Him with a view to an administration suitable to the fullness of the times, that is, the summing up of all things in Christ, things in the heavens and things on the earth. In Him also we have obtained an inheritance, having been predestined according to His purpose who works all things after the counsel of His will, to the end that we who were the first to hope in Christ would be to the praise of His glory. In Him, you also, after listening to the MESSAGE OF TRUTH, THE GOSPEL OF YOUR SALVATION—having also believed, you were sealed in Him with the Holy Spirit of promise, who is given as a pledge of our inheritance, with a view to the redemption of God’s own possession, to the praise of His glory." (Ephesians 1:3-14)
"...God has placed the members, each one of them, in the body, just as He desired." (1 Corinthians 12:18)
Humanity does not join the church (the body of Christ), but each human will be placed into it by God when it is their predestined time to believe the "message of truth, the gospel of your salvation" - the good news that Jesus is the Savior of the world! For most people that time will be after they have been resurrected to life and appear before God at the Great White Throne.