Exodus 15:3 says, “The LORD is a warrior; the LORD is his name” (NIV). The New King James Version translates “the LORD is a warrior” as “the LORD is a man of war.”
Romans 15:33 says, “The God of peace be with you all. Amen.”
Is this a contradiction? Can someone be at war and be peaceful at the same time? The answer is yes. Many nations, like the United States, tend to go to war so that they can have peace. (Yes there have been nations and people who love war, but many people and nations do not).
God is a God of peace. He originally created a perfect world that was peaceful. And God will restore that peaceful world after Christ returns. That peaceful world was disrupted because of mankind’s rebellion against God. Just like a nation of peace will go to war to restore peace, God has gone to war against sin and evil in order to restore his once perfect creation.
We must also look at the context of the verses above to understand them properly. In the first passage, the Israelites had just been led out of Egypt by God who fought against the Egyptians through his mighty hand. Exodus 15 takes place right after the crossing of the Red Sea when the Egyptians were drowned in the sea.
Another point to remember is that God is peaceful towards those who have faith in him. Paul is speaking to Christians in Romans 15:33. This peace may not be a complete peace in this life. Trouble will still come for believers in this sinful world. The peace today is God’s comfort. However, Isaiah 48:22 specifically says, “’There is no peace,’ says the LORD, ‘for the wicked.’”
God is both a God of peace and of war. He is at war against sin and those who reject him. However, he is a lover of peace and will restore peace in his creation at the proper time.