Lectionary woes

Really, seriously, what are we supposed to say about this?

What can we say about a God who asks a father to sacrifice his son? What can we say about a father who agrees? How do we not turn this into further violence by saying God later does the same thing to God’s own son, except without the providing-an-alternate-thing-to-slaughter bit?

Before I give up on this passage and decide to preach, er, Romans or something, I want to mull it over. Is there a word of grace here? Thoughts, people?