Scripture is literally full of references to people being (or having the potential to be) God's children. Indeed, this close parental relationship is implied from the very beginning of those writings. We read in Genesis: "Then God said, 'Let us make human beings in our image, to be like us. They will reign over the fish in the sea, the birds in the sky, the livestock, all the wild animals on the earth, and the small animals that scurry along the ground.' So God created human beings in his own image. In the image of God he created them; male and female he created them." Genesis 1:26-27 I think that the NLT (New Living Translation) better reflects the meaning of the original Hebrew than the KJV (King James Version). The Hebrew words imply a shadowy likeness or a similitude of the original, not a perfect copy. Strong's Concordance
According to the Gospel of John, the very mission of Jesus Christ was intimately connected to the establishment of this parent-child relationship between humans and the Divine. We read there: "But to all who believed him (Jesus) and accepted him, he gave the right to become the children of God." John 1:12 Once again, I think that the NLT captures the meaning of the original Greek better than the KJV. In the KJV, this passage is rendered as "sons of God." Nevertheless, the Greek word "teknon" implies offspring or children. Strong's Concordance Hence, the concept of children applies to both males and females.
Later, John wrote: "See how very much our Father loves us, for he calls us his children, and that is what we are! But the people who belong to this world don't recognize that we are God's children because they don't know him. Dear friends, we are already God's children, but he has not yet shown us what we will be like when Christ appears. But we do know that we will be like him, for we will see him as he really is." I John 3:1-2 Notice that John speaks of us as God's children in the Present Tense. Moreover, he makes it clear that we do not fully know/understand/comprehend what we will be in the future.
Likewise, the Apostle Paul quoted Isaiah when he wrote to the saints at Corinth: "No eye has seen, no ear has heard, and no mind has imagined what God has prepared for those who love him." I Corinthians 2:9 Then he goes on to say that God has given us a glimpse of that future through the indwelling of his Holy Spirit. verse 10
Indeed, Paul wrote to the Christians at Rome: "For all who are led by the Spirit of God are children of God. So you have not received a spirit that makes you fearful slaves. Insead, you received God's Spirit when he adopted you as his own children. Now we call him, 'Abba, Father.' For his Spirit joins with our spirit to affirm that we are God's children. And since we are his children, we are his heirs. In fact, together with Christ we are heirs of God's glory. But if we are to share his glory, we must also share his suffering. Yet what we suffer now is nothing compared to the glory he will reveal to us later." Romans 8:14-18
Hence, whatever it means to be God's children, that meaning has not yet been fully revealed to our minds. Nevertheless, John and Paul assure us that it will be wonderful and beyond our wildest expectations!
The author of the Epistle to the Hebrews wrote: "God, for whom and through whom everything was made, chose to bring many children into glory. And it was only right that he should make Jesus, through his suffering, a perfect leader, fit to bring them into their salvation. So now Jesus and the ones he makes holy have the same Father. That is why Jesus is not ashamed to call them his brothers and sisters. For he said to God, 'I will proclaim your name to my brothers and sisters. I will praise you among your assembled people.' He also said, 'I will put my trust in him,' that is, 'I and the children God has given me.'" Hebrews 2:10-13
Brethren, Jesus Christ got into trouble with the Jewish and Roman authorities for claiming to be the Son of God. They thought that his claim was blasphemous. What about you? Are you prepared to boldy assert your claim to be one of God's own children?