Aloha, no offence taken at your post, you raised questions that I used to ask myself. Although I was brought up in a Christian household and accepted Christ as a young teenager, it still took me years to grasp the concept of the Cross - Why did Jesus die? Did he in fact HAVE to die, was that the only way? (Looking back it was probably Satan planting huge seeds of doubt in my mind as to whether I was actually saved or not.) Why couldn't God have found another way, instead of sending his son to be killed - he parted the waves of the Red Sea to save the Israelites from captivity in Egypt, couldn't he have done something similar?
Why couldn't God just have forgiven us? Because God never compromises on his holiness, he must totally and utterly shun sin and in his justice he must punish it and requires payment by the shedding of blood. God just couldn't ignore our sin as if it hadn't happened. But out of his immense love and mercy for all of us he sent his only Son to pay the penalty.
Bloss' story was an excellent example of God's love in sending Jesus to die for us - but if the man in the cell had not accepted the gift of the cheque after the judge had given up everything so he could pay off his debt, he would still be in the cell now. Christ?s death is of no use unless we receive his gift of sacrificial payment for our sins.
And I agree that 2000 years on it may seem strange to sacrifice a child or an animal, but it would have been very significant to the Jews of the day as the shedding of blood was very important through the sacrifice of lambs etc. as an atonement of their sins, but Jesus was the sinless Lamb of God, and he paid the price in full, animal sacrifice was no longer necessary.
If I could list the people I would lay my life down for, it would be fairly short - ds, dh, Mum, brother... but if I had to list people who I would sacrifice my child for, well, it would be non-existent, no-one would come close. But because God loves us so very much, he was willing to do just that - if that doesn't make me grateful to him I don't know what does!