From a broad search I selected only those people that I personally know have given much Christian fruit in my experience. To be able to judge your experience versus mine we'd need to establish agreed standards of judgment. "Did you want to establish how you can be sure a birth Jew has fully embraced his confession of Jesus Christ as God and Lord so that we can make it a more formal debate?" Is it impossible for a birth Jew, or is there a standard the church can use to be sure they are not subverters? Nobody expects the Spanish Inquisition!