a. All Jews who believe the Gospel are saved the same as Gentiles who believe the Gospel.
b. I believe that scripture teaches that God will spiritually revive Israel the nation.
So we agree that justification has always been by faith and not by works. No one can be righteous enough to be just before God on their own merits. Not even close. Our best works themselves are tainted by a degree of sinfulness.
I am more speaking about preachers and pastors and writers and teachers that teach security of the believer. Most teach the necessity of holiness for believers. You can't put everyone who teaches Security of the Believer into the same basket.
Everyone who has ever been baptized with the Holy Spirit is in the body of Christ. 1 Corinthians 12:13
Peter was baptized with the Holy Spirit. Acts 2
It follows then that Peter was part of the body of Christ.