'Sons' in the Bible

so then, understand that those who believe are the sons of Abraham.

For in Christ Jesus you are all sons of God through faith.

to redeem those who were under the law, so that we may be adopted as sons with full rights.

And because you are sons, God sent the Spirit of his Son into our hearts, who calls "Abba! Father!"

For it is written that Abraham had two sons, one by the slave woman and the other by the free woman.