Monsignor Pope Ping!
True. Satan was not part of this transaction except for his attempt to distract Jesus from His purpose in the desert. In a way, God bought us back from Himself. We were under His curse brought about by our breaking of the Covenant.
When the Israelites entered Canaan, they were given the choice between obedience and infidelity; the blessing and the curse. They chose the curse. God swore upon Himself that His promise to Abraham would be fulfilled. He took the ultimate consummation of the curse upon Himself and paid the price of justice on the Cross. On the Cross is the physical embodiment of justice and mercy; it is punishment and redemption; death and rebirth; pure love for those who continually reject Him.
Sean Astin (Sam from LOTR), made a movie about Hosea: Amazing Love.