Let’s begin with a statement the Lord says of Himself in Malachi 3:6, “For I am the LORD, I change not.”  The God of the Old Testament is the same God of the New Testament. 

In Exodus 34:6-7 we read these words the Lord spoke to Moses, “And the LORD passed by before him, and proclaimed, The LORD, The LORD God, merciful and gracious, longsuffering, and abundant in goodness and truth, Keeping mercy for thousands, forgiving iniquity and transgression and sin, and that will by no means clear the guilty…”  The Lord declares that He is merciful and gracious and that He is also righteous in not clearing the guilty.  In the New Testament, the Lord speaks of His righteousness in Hebrews 12:6, “For whom the Lord loveth he chasteneth, and scourgeth every son whom he receiveth.”  He speaks of His mercy and holiness in many places, particularly in that most well known verse John 3:16, “For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life.”

While some may get an impression of the Lord being harsh in His punishment of sin in the Old Testament, we read in Romans 1:18, “For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who hold the truth in unrighteousness.”  The Lord’s hatred of sin has never changed, and He will harshly judge sin in the unrepentant heart.

1 Corinthians 10:11 tells us, “Now all these things happened unto them for ensamples: and they are written for our admonition, upon whom the ends of the world are come.”  Many of the events of the Old Testament are recorded so that we might learn from them.  When we read of times when the Lord ordered the complete destruction of a city or tribe of people, this was for our learning.  For example, we read in 1 Samuel 15:2-3, “Thus saith the LORD of hosts, I remember that which Amalek did to Israel, how he laid wait for him in the way, when he came up from Egypt. Now go and smite Amalek, and utterly destroy all that they have, and spare them not; but slay both man and woman, infant and suckling, ox and sheep, camel and ass.”  This sounds horrible, doesn’t it?  The Amalekites were a terrible people who had treated the Israelites cruelly. (Read Exodus 17:8 and Deuteronomy 25:18 for examples.)  However, when we realize that the Lord wants us to learn to destroy all those things in ourselves that would divide our hearts from Him, we see His wisdom in causing these situations.  The history of the Israelites’ sins and punishments was written and recorded by God in His Word, for the benefit of all succeeding generations, and particularly for us, who live in the last ages of the world, to warn us to avoid the like sin, that we may escape the like punishments.

The God who pours out his wrath against sin in the Old Testament is the same God who will inflict the vengeance of eternal punishment on those who do not believe in the Lord Jesus Christ.  We read in 2 Thessalonians 1:7-10, “And to you who are troubled rest with us, when the Lord Jesus shall be revealed from heaven with his mighty angels, In FLAMING FIRE TAKING VENGEANCE on them that know not God, and that obey not the gospel of our Lord Jesus Christ: Who shall be punished with EVERLASTING DESTRUCTION from the presence of the Lord, and from the glory of his power; When he shall come to be glorified in his saints, and to be admired in all them that believe (because our testimony among you was believed) in that day.”

At the same time, the God who in the New Testament is described as loving the world enough to send his Son for their salvation (John 3:16) is the same God who revealed himself to Moses as “merciful and gracious, slow to anger, and abounding in steadfast love and faithfulness, keeping steadfast love for thousands, forgiving iniquity and transgression and sin” (Exodus 34:6–7).

When we carefully read our bibles, we will see that that God is not different from one testament to another and that God’s wrath and His love are revealed in both testaments.  (401.4)