"Dad," Eli asks me in a whisper, "why did Abraham kill Isaac?" We are in his bed, looking out at the darkening sky and listening to crickets. In his bed across the room, our Isaac is already asleep, a lamb clutched to his chest, his mouth agape.

"He didn't kill Isaac, remember?" I kiss Eli on the head. "God sent a ram to be sacrificed in his place."

"I thought Abraham killed him."

"Nope."

"But why did God tell him to kill Isaac?"

It's more complicated to explain than some might think. As I explain how God wanted to stretch Abraham's faith, and how Abraham thought God would bring Isaac back to life, and how God was even then writing the story of Jesus, I feel myself coming to that place where I am struggling: the doctrine of propitiation, of score settling, of wrath. In my mind I can hear the fussy answers from self-satisfied types who take a masochistic delight in the Angry God. I hear a string of preachers from my own childhood, warning me to be a good boy or go to hell. I remember the nightmares I still have, of demons coming to take me there.

"Why did Jesus have to die?" Eli asks.

A good Presbyterian would tell him the wages of sin is death, and that a price had to be paid, a sentence served. Instead I tell him that when sin came into the world, it made all of us sick. "Do you know how when you do something bad, it makes you feel bad inside?" Eli nods. "The blood of Jesus will make all of us well," I tell him. "It works slower on some than others, but it's the medicine we need. And one day he will come back, with all his angels, and then all the evil things in the world will try to fight them, but they will lose, and then none of God's children will be sick any more."

Eli lays his head down on my arm. He asks me why we can't see God, and why God made the Devil, and when Jesus will come. I tell him about heaven, and how all things will be made right one day, and that Jesus will never let him go. I put my head next to his, and breathe in his scent of wet puppies and toothpaste. "I will always love you," I tell him, "no matter what."

"I know."

Somewhere beyond the crickets and our line of hedge trees is the world into which one day he will venture. Maybe he will have a more accurate understanding of whether the blood is a cure, or a debt paid, or both. Years ago the answers seemed more certain to me.

I think sometimes my children will leave me with more questions than answers. But they will go knowing that they are loved by their God, and by their father. If you ask me what is my creed, this is what I will tell you: that I am selfish through and through, but for them to know those two things I will lay down my life, walking all the chastened paths along which a parent must stumble.