God's Love for the World

If there is one thing that Christianity, in all its various stripes and manifestations, can agree on is the refrain from 1 John 4:8, 16 - "God is Love". He is the essence of what love is, his actions define love, and love is only knowable by us because God manifests himself to the world. But, the manner and means by which God loves the world, a world filled with sin, hatred, jealousy, and spite, is quite another thing altogether. John 3:16 is perhaps the best-known biblical verse of all time and is able to be repeated by people who have never broken open a Bible, never heard a sermon, and have never darkened the door of a church. But what is John saying in this verse?