John 3:16 (among others) tells us that God sent his Son to save us. I’ve heard some people comment that no parent could send their child to such a gruesome torture and death. So rather than being sent, Jesus offered to sacrifice himself. Is this just a matter of semantics, or does it make a difference whether God offered his Son or Jesus offered himself?
It is not an either/or. It is a both/and. God the Father sent his Son into the world, and in so doing offered his Son for the sake of our salvation. God the Son freely chose to enter the world and to offer up his life as a sacrifice for sin.
As for the objection given to you that “no parent could send [his] child to such a gruesome torture and death,” that is true for human parents. No human parent could do that, and no human parent could be praised if he did do that. But this is an argument by analogy, and there is very limited value to inferring what God might do based on human experience. God is so entirely other from humans that we cannot condemn God for doing something inexplicable to human understanding based solely on the fact that it is inexplicable to human understanding. That is one reason why Christians accept that much of what we know about Christianity is ***mystery***—mystery in the sense that there are certain divine truths that we can know something about but not everything.