I marvel that ye are so soon removed from him that called you into the grace of Christ unto another gospel: Which is not another; but there be some that trouble you, and would pervert the gospel of Christ. But though we, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed. Galatians 1:6-8 KJV
Many books have been written but only one by the hand of God. This begs the wuestion: Why believe anything else?
Every Scripture is God-breathed (given by His inspiration) and profitable for instruction, for reproof and conviction of sin, for correction of error and discipline in obedience, [and] for training in righteousness (in holy living, in conformity to God’s will in thought, purpose, and action),
2 Timothy 3:16 AMPC