If you don't lose anything then you sacrificed nothing.
If God is an all-powerful being, and Jesus is God then he sacrificed nothing on the cross.
If Jesus was just a normal human then he sacrificed everything for us.
Matthew 12:32 (NIV)
Anyone who speaks a word against the Son of Man will be forgiven, but anyone who speaks against the Holy Spirit will not be forgiven, either in this age or in the age to come.
God doesn't receive human/sinner insults, that's totally not acceptable. That's why God never left His true name to humans. He only told humans that "I AM who I AM".
Jesus is God the Son, insulting Jesus should be treated the same as insulting the Holy Spirit. However in a sense through receiving insults from humans as the strongest punishment of God He thus gains the right to save humans.
God cannot be harmed physically. However, He can be harmed while knowing that His creation sins. He can be harmed by incarnating as humans to suffer as humans and to bring blasphemy to His name ever since the crucifixion until now and till the end of this world.
God will only reveal His name to humans after everything is accomplished. For the same reason, Jesus will have a new name by then.
Revelation 3:12 (NIV)
The one who is victorious I will make a pillar in the temple of my God. Never again will they leave it. I will write on them the name of my God and the name of the city of my God, the new Jerusalem, which is coming down out of heaven from my God; and I will also write on them my new name.
The sacrifice of one human won't justify the saving of unlimited number of humans. Only God's self-sacrifice will do.