Contradiction with John 14:6
John 14:6 claims exclusivity in coming to God through Jesus, which can contradict the inclusive gathering of all nations and tongues in Isaiah 66:18.
John 14:6: Jesus saith unto him, I am the way, the truth, and the life: no man cometh unto the Father, but by me.
Contradiction with Matthew 7:13-14
These verses suggest a narrow path to life, while Isaiah 66:18 speaks of gathering all nations, implying a broader inclusion.
Matthew 7:13-14: Enter ye in at the strait gate: for wide [is] the gate, and broad [is] the way, that leadeth to destruction, and many there be which go in thereat: [strait: or, narrow]
Contradiction with Romans 11:7-8
These verses imply a partial hardening of Israel and a smaller remnant chosen by grace, contrasting with the inclusive gathering of Isaiah 66:18.
Romans 11:7-8: What then? Israel hath not obtained that which he seeketh for; but the election hath obtained it, and the rest were blinded [blinded: or, hardened]