What is the worst religion in existence?

[Anomalocaris]

That's a rather transactional view of love.  I've never had children, but if I did, I would exist for their benefit, not the other way around.

I speaking of the children's love toward the parents.

children do not owe parents love by default because children did make their parents have children.   it was parent’s choice and therefore parent’s obligation for making the choice.  

children don’t need to earn love,  it is owed to them for being unavoidably the product of parent’s choice.   parent’s on the other hand must earn children’s love, it is not owed to them because no one, above all not their children, made them have children. 

your mentality is the result of ancient primitive barbarous tradition of parents abusing their position of superiority to extort unearned deference.    your god is an artifact of that barbarous tradition.