All are children of God by creation,
Acts 17:26 He made from one man every nation of mankind to live on all the face of the earth, having determined their appointed times and the boundaries of their habitation, 27 that they would seek God, if perhaps they might grope for Him and find Him, though He is not far from each one of us; 28 for in Him we live and move and exist, as even some of your own poets have said, 'For we also are His children.' 29 Being then the children of God, we ought not to think that the Divine Nature is like gold or silver or stone, an image formed by the art and thought of man.
But all are not children of God by the new creation, the kingdom of God and the love of God
They said to Him, "We were not born of fornication; we have one Father: God." 42 Jesus said to them, "If God were your Father, you would love Me, for I proceeded forth and have come from God, for I have not even come on My own initiative, but He sent Me. 43 Why do you not understand ]what I am saying? It is because you cannot hear My word. 44 You are of your father the devil, and you want to do the desires of your father. He was a murderer from the beginning, and does not stand in the truth because there is no truth in him. Whenever he speaks [n]a lie, he speaks from his own nature, for he is a liar and the father of lies. 45 But because I speak the truth, you do not believe Me. 46 Which one of you convicts Me of sin? If I speak truth, why do you not believe Me? 47 He who is of God hears the words of God; for this reason you do not hear them, because you are not of God."