There are many ways to look at this. First, God does not demand; He asks. We determine if we comply. We are, after all, given free will. But there is a problem with free will, my use of my free will has repercussions for more than just me. If I, as a father, spend money on a new car, my family would feel the repercussions.
Back to the question at hand, so why does God ask so much from us? God asks much of us because He has given us much. Not only did God create us, but the God who is existence itself, keeps us in existence, too. But greater than both of these is what He did for us through Jesus’ passion and death. “Much will be required of the person entrusted with much” – [Luke 12:48]
So, if God asks this of us, He allows us to say yes freely. If we say no, He will accept our choice. A choice that lands one in Hell. To truly be able to love, one must be free to choose between love and hate. God will not force us to love Him.
If you love someone, set them free.
If they come back they're yours; if they don't they never were. – Richard Bach