God cursed Cain for the horrible thing he did to Abel.
I have placed you under a curse and you can no longer farm on the soil. If you try to grow crops, the soil will not produce anything. You will be homeless and wander the earth.
God places a mark on Cain so that everyone who comes in contact with him, will stay away from him and will not kill him.
This punishment is too hard for me to bear! Anyone who finds me wandering will kill me !
I will put a mark on you to warn everyone. If anyone kills you, seven lives will be taken in revenge