After these things God tested Abraham and said to him, “Abraham!” And he said, “Here I am.” He said, “Take your son, your only son Isaac, whom you love, and go to the land of Moriah, and offer him there as a burnt offering on one of the mountains of which I shall tell you.” (Genesis 22:1-2)
Isaac wasn't Abraham's only son. Was God wrong?
And Isaac said to his father Abraham, “My father!” And he said, “Here I am, my son.” He said, “Behold, the fire and the wood, but where is the lamb for a burnt offering?” Abraham said, “God will provide for himself the lamb for a burnt offering, my son.” So they went both of them together. (Genesis 22:7-8)
And Abraham lifted up his eyes and looked, and behold, behind him was a ram, caught in a thicket by his horns. And Abraham went and took the ram and offered it up as a burnt offering instead of his son. (Genesis 22:13)
God provided a ram, not a lamb.
God wasn't wrong, and Abraham wasn't wrong about God. This event was about something much bigger and better. Later, in the same place, God did provide a lamb for the sacrifice, his only Son.
“For God so loved the world, that he gave his only Son, that whoever believes in him should not perish but have eternal life. (John 3:16)
The next day he saw Jesus coming toward him, and said, “Behold, the Lamb of God, who takes away the sin of the world! (John 1:29)