Satan hated Jesus when he sat on the throne in Heaven. Satan hated Jesus even more when he lost his position in Heaven. Satan's hate grew even more when Jesus pledged his life to redeem the human race.  

God who loved his son allowed him to go to a world as a helpless baby that Satan claimed to dominate. God allowed his son to experience all the trials and temptations this world has to offer. He did this at the risk of failure and eternal separation. Jesus taking on humanity was susceptible to failure.  

As a father of a four month old baby, I understand the desire to protect my son from the dangers of this world. I would be devastated if something were to happen to my baby. Yet, God who knew the dangers and had perfect love was willing to risk his son so that we might live. He did this for a human race marred in sin and full of hatred.