That assertion is rank nonsense.
Of course it isn't. The New Testament canon is precisely that: a canon, or rule of faith.
What Christian community has ever rejected the Pauline corpus?
Even the tiniest, unaffiliated nondenominational congregations recognize the canon of the New Testament as inviolable.
Every other Christian denomination - Catholic, Orthodox, Oriental Orthodox, Anglican, Reformed, Lutheran, Methodist, Pentecostal, Baptist, etc. includes the whole New Testament as a foundational element of their faith.