Who is responsible?

In the case of evil (i.e. some form of bad happening)

who is the ultimate responsible cause?

The reformers and puritans say it has to be God (as of course Augustine)

God is the first cause, yet not the author or the agent (second cause) of the evil

let's put this relationally:

Let's say my son loves to touch things he shouldn't
So first I tell him not to
Then after a while, I stop telling him, since I've told him 100x before
then I see him going to pull at a chair
I know completely what is going to happen
He will pull the chair, it will fall on him, he will get slightly hurt and cry

Now, who pulls the chair? - my son
who causes the evil - me of course - because in this scenario 'i am sovereign'

in legal cases - it's the one who is 'in-charge' of a situation
who is equally at fault if he knows what his subordinates have done, and has not stopped them
they are both tried and found guilty of the same crime

Yet of course in causing evil (which God admits several times),
His ultimate purpose is good - just like any parent
why must there be evil?
because we are naive children

what is the mystery of the entrance of evil into the world?
i like this one: