The word "adopt" is a faulty translation.
Jesus Christ is the Messenger from the Father.
What he says is true.
No, it's not faulty. Multiple English translations, where the translations are peer reviewed, use the word adopt.
The problem seems to be that you deny the deity of Jesus and make him lower than God. Jesus is not a "messenger" or angel. Jesus is God, the Creator and sustainer of all things.
What God says is that He adopted us from before the foundation of the world.
John 1:1-5,9-14
[1]In the beginning the Word already existed. The Word was with God, and the Word was God.
[2]He existed in the beginning with God.
[3]God created everything through him, and nothing was created except through him.
[4]The Word gave life to everything that was created, and his life brought light to everyone.
[5]The light shines in the darkness, and the darkness can never extinguish it.
[9]The one who is the true light, who gives light to everyone, was coming into the world.
[10]He came into the very world he created, but the world didn’t recognize him.
[11]He came to his own people, and even they rejected him.
[12]But to all who believed him and accepted him, he gave the right to become children of God.
[13]They are reborn—not with a physical birth resulting from human passion or plan, but a birth that comes from God.
[14]So the Word became human and made his home among us. He was full of unfailing love and faithfulness. And we have seen his glory, the glory of the Father’s one and only Son.