Why does God take revenge !?

God is loving and forgiving.

The lord is jealous and vengeful.

These are opposites.

What is the opposite of God?

The universe works like a mirror.

It reflects back at us exactly what we show it. This is a learning tool that teaches us the effects of our actions.

To see it as punishment is missing the point of the exercise.

When you were a child, did your parents never punish you for some of your mistakes? Did that stop them from loving you? Did you ever feel that your parents are taking nay sort of revenge on you? Your question arises from confused thinking.

Believing in gods leaves lots of unanswered questions. We suffer because the human society is imperfect.

God takes revenge because He is rude.

It is better a millstone be tied around your neck and tossed in the sea, than to offend or despise a little one...I just wonder, how many little ones have been offended or despised? Collateral damage does count in his eyes.

The people who wrote the ancient holy texts did not know why weather phenomena happened so they blamed it on god or gods.

Sometimes you need to distinguish between the idea of God punishing anyone, and when he simply withdraws his grace and protection from people. If we reject God and his care, then he might well respect our decision and just leave us to the mercy of satan. That is not punishment, it is us getting what we ask for.