Why is there a big difference between the image of God in the old testament and in the new testament?

Why God looks so different in the old testament and in the new testament? It seems God is so angry in the OT and so living in the NT?

They are the same. i think

God’s love has not changed, but man’s salvation requires a process, and therefore a different way of leading.

I don’t think so. When I read Old Testament, I feel God is a God of love.

Deuteronomy24: 21 When you harvest the grapes in your vineyard, do not go over the vines again. Leave what remains for the foreigner, the fatherless and the widow.

Reading God’s law, could not imagine how careful God’s love is. Even modern laws can’t reach this level. Who cares how you pick up your grape? Each law is God’s love for us.

Why sometimes God’s law looks harsh? Because our life will be destroyed in sin. If you love deeper, you have more responsibility. And it will be not easy to see your children to commit sin.

In New Testament ,Jesus sometimes says some harsh word.

34 You brood of vipers, how can you who are evil say anything good? For the mouth speaks what the heart is full of. (Matthew12:34)

Can you imagine someone say to you: you are brood of vipers.

God never changes from Old Testament to New Testament.

God is the same yesterday, today and tomorrow. (see Numbers 23:19, Hebrews 13:8, James 1:17 )

If you have read your Bible more than once, cover to cover, and you are a saved Christian, you would see how utterly consistent God is!

He waits for hundreds of years sometimes before finally condemning a constantly rebellious and evil people! His patience is so far beyond ours we cannot really imagine it. But we CAN read about it!

Try, well, reading Genesis through Revelation. Then read it again. Read it for yourself, don’t just repeat the questions and doubts you hear around you. Find out for yourself!

And, just in case you do not have access, this site is free and supports many languages:
https://www.biblegateway.com