To love someone is to take responsibility for them. Love can only be seen in actions. Expressions of love are just wishful thinking. The lesson of the Good Samaritan shows this rightly: to love is to take responsibility, it's a physical, real action that the lover takes and performs for the loved.
Holy Mary made this commitment to God, to be Responsible for bringing Him into the world, to be Responsible for His nurture to adulthood. These are actions, not words. It is for Her actions that we call Her Blessed, not for the promise.
When we speak of God's love, remember that He holds all things in existence. This is The Supreme Act, to be Responsible for everything.
The Devil still exists, what are we to make of this? That God is Responsible for him! God doesn't stop being Responsible for you when you fail to live up to your responsibilities either. Does this mean that God creates and maintains evil, No, it means that he takes Responsibility for giving Lucifer free-will, and the consequences of that.
The issue of Free-will is vital here, without free-will we cannot Take Responsibility. If you are given responsibility as a slave, you perform your duty out of fear. If you take responsibility freely, then you perform your duty as a free gift.
Jesus shows us by His voluntary acceptance of the Cross that God still takes responsibility for His creation. Death appears to us to be the termination of existence, but Christ shows this is not so. As long as we are the Responsibility of God we cannot be terminated. God shows us that He will not forget His responsibility to maintain us in existence.
Everything we know about God, about Jesus, about the Father, about the Holy Spirit, shows us how He takes responsibility for His creation, all of it. He has never, to our knowledge, snuffed out any part of it, forgotten it, and allowed it to un-exist. Thus we can say, with confidence, that God is Love.