Romans 8:9

8:9 You, however, are not in the flesh but in the Spirit, if indeed the Spirit of God lives in you. Now if anyone does not have the Spirit of Christ, this person does not belong to him.

Romans 8:14-16

8:14 For all who are led by the Spirit of God are the sons of God. 8:15 For you did not receive the spirit of slavery leading again to fear, but you received the Spirit of adoption, by whom we cry, “Abba, Father.” 8:16 The Spirit himself bears witness to our spirit that we are God’s children.