Could you honestly love a child not biologically yours just like your own?

So say if you had step children as well as your own bio children. Do you honestly think you could love that child on the same level? Of course you would love them, but I mean on that seem deep meaningful level as your own?

Like for my own children I would lie down and die for them in a second, without even thinking about it. But I couldn’t see me feeling that strongly for another child.

Of course I would care for them, love and nurture, but I don’t know if I would love them enough to DIE for them like my own.

For example I have nieces and nephews which I love of course and I would protect them as much as I could , but I wouldn’t die for that then like my own kids?

Anyone have experience with this? How did / do you feel? Or how do you think you would feel?