No, we are no all children of God.
Only those who put their faith in Him.
John 1:11-12 He came to his own, and his own people did not receive him. But to all who did receive him, who believed in his name, he gave the right to become children of God, who were born, not of blood nor of the will of the flesh nor of the will of man, but of God.
I respectfully disagree. God created Adam and Eve and we all evolved from them . That tells me we are all children of God. Some have strayed from his teachings but that is where free will comes in.