Genesis 22:5 And Abraham said to his young men, “Stay here with the donkey; the lad and I will go yonder and worship, and we will come back to you.”
Abraham knew his son was coming back with him. Now, weather he was aluding to the LORD resurrecting him or that Isaac wasnt the sscrifice at all. Faith & trust in the LORD brings us to an understanding that He is always good, just, righteous. Nothing He calls us to do is wrong, sin, or meaningless. This is going to become an amazing passage about the Lamb of God, set to be sacrificed long before the cross. The road to the cross was already set in motion at Genesis 3.