Is the God of the Old Testament different from the God of the New Testament?

The God of the Old Testament is not different from the God of the New Testament. He is the same God with the same character, speaking at different moments in history. The idea of two gods, one angry and one loving, comes from reading only half the texts on each side.

Scripture declares one God who does not change

The text itself settles the question. In Malachi 3:6, God says He does not change. Hebrews 13:8 says Jesus Christ is the same yesterday, today and forever. James 1:17 speaks of the Father of lights, with whom there is no variation or shadow of turning.

The New Testament never presents itself as a new god, either. The apostles preach the God of Abraham, Isaac and Jacob (Acts 3:13). Jesus says He did not come to abolish the Law and the Prophets but to fulfill them (Matt 5:17). And when Paul explains the work of Christ, he keeps quoting Genesis, the Psalms and Isaiah, because he sees one story.

A word on terms: saying God does not change is not saying He never responds. The Old Testament shows Him turning back from an announced punishment when people repent (Jonah 3:10). That is faithful character, not shifting moods. This theme has its own article, "Does God change His mind?"

Grace in the Old Testament

Read the Old Testament closely and you find mercy on nearly every page. When God passes before Moses, He introduces Himself as compassionate, gracious, slow to anger, abounding in love and faithfulness (Exod 34:6-7). That line returns like a refrain in Psalm 103:8-10, Nehemiah 9:17 and Joel 2:13.

Jonah shows it in an odd way. He ran from Nineveh because he knew God is gracious and compassionate (Jonah 4:2). Jonah knew the God of mercy well, and that was exactly his problem. In Hosea 11:8, God asks how He could give up on Ephraim, and His heart recoils within Him. In Ezekiel 33:11, He says He takes no pleasure in the death of the wicked.

Old Testament salvation is grace too. God brings Israel out of Egypt before giving the Law, and Abraham was counted righteous by faith (Gen 15:6). Anyone who pictures an Old Testament of merit and a New one of grace overlooks Romans 4, where Paul uses Abraham and David as examples of grace.

Judgment in the New Testament

The reverse needs saying as well. The New Testament is far from soft. Ananias and Sapphira fall dead after lying to the Holy Spirit (Acts 5:1-11). Paul writes that the wrath of God is revealed from heaven against all ungodliness (Rom 1:18). Hebrews 10:31 says it is a fearful thing to fall into the hands of the living God, and Hebrews 12:29 says our God is a consuming fire, echoing Deuteronomy 4:24.

Revelation closes the Bible with a Rider who judges and wages war in righteousness (Rev 19:11-21). And one fact tends to surprise people: the person who speaks most about hell in the Gospels is Jesus. He warns about the One who can destroy both soul and body in hell (Matt 10:28), describes the final separation (Matt 25:46) and speaks sternly about sin (Mark 9:43-48). The gentle Jesus who welcomes children is the same one who overturns tables in the temple.

Jesus reveals the Father, not a different God

When Philip asks to see the Father, Jesus answers that whoever has seen Him has seen the Father (John 14:9). That shuts the door on the idea that the Son corrects the Father. The Son shows the Father clearly, and what He shows matches Exodus 34: compassion and truth, forgiveness and justice, together.

Someone may cite John 1:17, where the Law came through Moses and grace and truth through Jesus. The contrast there is about fullness, not two gods. Grace was already in the Law; in Christ it stands before you in person. The cross shows this better than any argument: God's justice against sin and His love for the sinner meet in one act (Rom 3:25-26).

What about the wars of Canaan?

This is the hardest objection, and it deserves an honest answer. Texts such as Deuteronomy 20:16-18 and the fall of Jericho in Joshua 6 command the destruction of whole cities. That is disturbing, and it should not be disguised.

Scripture offers some pointers, without claiming to settle everything:

• God presents the event as judgment on wickedness that had ripened, not as favoritism toward Israel. He told Abraham the sin of the Amorites was not yet complete (Gen 15:16), and Israel is told the land is not given for its own righteousness (Deut 9:5).
• Israel is judged too. The same land would vomit Israel out if it did the same things (Lev 18:24-28), and the exile shows this was serious.
• The "destroy everything" language seems, in part, to be the idiom of war. Judges shows peoples who remained afterward (Judg 1:27-36), and Scripture counts Rahab, a Canaanite, among those welcomed (Josh 6:25).

Hard questions remain, especially about the children and about what exactly happened. Faithful Christians read these passages differently, and saying "I do not know everything" is more honest than forcing a neat solution. What we can affirm is the starting point: the Judge of all the earth does what is right (Gen 18:25), and the same text that records judgment records centuries of patience before it.

Marcion's error and what it changes for you

Around the year 140, Marcion taught that the God of the Old Testament was inferior and cruel, and that Jesus came from another, good God. The church rejected him. He had to cut parts of the New Testament to hold the idea, because the New Testament is stitched with the Old from start to finish. Whoever separates the two ends up with no Bible at all.

This matters for two reasons. First, you can read Leviticus and the Prophets without fear of meeting a stranger: this is the Father of Jesus. Second, you cannot shrink God to what suits you. A God of tenderness alone would save no one from sin, and a God of judgment alone would not have sent the Son. The God of the Bible is holy and loving at once, and the cross is where you see both together.