The Old Testament God vs The New Testament God

There seems to be much evidence that the God of the Old Testament was a stern, unloving, and authoritarian god. When the Israelites came into the land of Canaan, God gave many commands that today's society finds repugnant and cruel. Disobedience to the law also brought swift and sometimes deadly punishment.

On the other hand, the God of the New Testament was all about turning the other cheek, loving one's enemies, and giving mercy. How can these two descriptions of God both be true? Are there two gods? Has the God of the Old Testament softened His heart and changed His mind and methods?

Oddly, we find both descriptions in the book of Hebrews.

Hebrews 12:18-21 (KJV)
¹⁸ For ye are not come unto the mount that might be touched, and that burned with fire, nor unto blackness, and darkness, and tempest,
¹⁹ And the sound of a trumpet, and the voice of words; which voice they that heard intreated that the word should not be spoken to them any more:
²⁰ (For they could not endure that which was commanded, And if so much as a beast touch the mountain, it shall be stoned, or thrust through with a dart:
²¹ And so terrible was the sight, that Moses said, I exceedingly fear and quake:)

As the Israelites came to Mount Sinai, they were met with sounds, sights, and commands that were terrifying. They couldn't touch the mountain or they would be killed. The voice they heard sounded like thunder, and there was fire, blackness, darkness, and tempest. Even Moses, the man of God, was exceedingly afraid.

The Old Testament God was certainly no one to mess around with! Wait . . . .

Hebrews 12:22-24 (KJV)
²² But ye are come unto mount Sion, and unto the city of the living God, the heavenly Jerusalem, and to an innumerable company of angels,
²³ To the general assembly and church of the firstborn, which are written in heaven, and to God the Judge of all, and to the spirits of just men made perfect,
²⁴ And to Jesus the mediator of the new covenant, and to the blood of sprinkling, that speaketh better things than that of Abel.

Instead, believers today come to Mount Zion, the city of the living God, the heavenly Jerusalem, angels, and men made perfect. This sounds so much better than the Old Testament God. Yes, they still come to God, the Judge, but they also come to Yeshua, the mediator of a new covenant, that speaks of better things than that of Abel (Old Testament saint with a pleasing sacrifice). Hebrews continues:

Hebrews 12:25-28 (KJV)
²⁵ See that ye refuse not him that speaketh. For if they escaped not who refused him that spake on earth, much more shall not we escape, if we turn away from him that speaketh from heaven:
²⁶ Whose voice then shook the earth: but now he hath promised, saying, Yet once more I shake not the earth only, but also heaven.
²⁷ And this word, Yet once more, signifieth the removing of those things that are shaken, as of things that are made, that those things which cannot be shaken may remain.
²⁸ Wherefore we receiving a kingdom which cannot be moved, let us have grace, whereby we may serve God acceptably with reverence and godly fear:

In this section, the writer of Hebrews revealed that he was making a comparison, although perhaps an unexpected one. In verse 25, the reader is cautioned not to refuse Him that speaks, meaning the before mentioned God of the New Testament. He then goes on to say that if the Israelites who refused the God of the Old Testament had not escaped, HOW MUCH MORE shall the refusers of the God of the New Testament not escape. This God of the New Testament will shake not only the earth, but heaven as well. In fact He will, in the future, bring much destruction upon the earth. Only His kingdom will not be moved, therefore let us have grace, whereby we may serve God with reverence and godly fear.

The writer of Hebrews seemed to have understood that the God of the Old Testament was viewed negatively and with fear, whereas the God of the New Testament was viewed positively and with love. But this comparison is inaccurate according to Hebrews. The passage ends with this:

Hebrews 12:29 (KJV)
²⁹ For our God is a consuming fire.

There is only ONE God, the God of Abraham, Isaac, and Jacob. He has, also, not changed His mind or methods. The God of the Old Testament is the same as the God of the New Testament. He was a consuming fire then and is He is a consuming fire now. He is not to be messed with.

But don't forget the description of the New Testament God! Even though God is a consuming fire, He is also love and mercy. For those who turn to Him, to serve and follow Him, there is abundant mercy and loving kindness. Yes, there is only One God of the Old and New Testament!