Peter erred in life and in doctrine. Paul might have dismissed Peter's error as a matter of no consequence. But Paul saw that Peter's error would lead to the damage of the whole Church unless it were corrected. Therefore he withstood Peter to his face. The Church, Peter, the apostles, angels from heaven, are not to be heard unless they teach the genuine Word of God.
Martin LutherThe heavenly blessing is to be delivered from the law, sin and death; to be justified and quickened to life: to have peace with God; to have a faithful heart, a joyful conscience, a spiritual consolation; to have the knowledge of Jesus Christ; to have the gift of prophecy, and the revelation of the Scriptures; to have the gift of the Holy Ghost, and to rejoice in God.
Martin Luther