Love Letter

I've heard, more than once, someone refer to the Bible as "God's love letter". I confess that I haven't received that many love letters in my life, but not one of them included accounts of war, a detailed architectural layout, or scathing denunciations of foreign governments. My question is, what sort of love letters are these people receiving?

If this is what their love letters tend to contain, I can understand why they're having so little luck at impacting the world for good.