How Could God Ask Abraham to Sacrifice His Son?

I've heard this one thrown around a lot of different ways, and most often as a criticism of God and His character.

Nancy Guthrie has a very good post on the Gospel Coalition blog today- "How Could God Ask That?"

Here's a quote-  "Why would God ask Abraham to offer his son as a sacrifice? Is God trying to teach us that we should be willing sacrifice what is most precious to us? No. This story is not recorded to inspire sacrifice to God. Instead, it paints in vivid colors the sacrifice of God. The point of this story is not to convince you that you must be willing to sacrifice to God what is most precious to you, but rather to prepare you to take in the magnitude of the gift when you see that God was willing to sacrifice what was most precious to him—his own beloved Son—for you."

Kinda changes the perspective, no?