"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." (John 1:12-13)
It is not by physical descent or by human efforts that one becomes a child of God, but by faith. He took action to redeem us by sending God the Son into this world. We obtain an inheritance in heaven that cannot perish or fade away.
Interestingly, the New American Bible Revised Edition has this footnote on a manuscript variant reading of John 1:13:
"...The variant “he who was begotten,” asserting Jesus’ virginal conception, is weakly attested in Old Latin and Syriac versions."
The Apostle Paul used adoption as a metaphor to communicate that we as believers partake of the inheritance that belongs to Jesus Christ:
"and if children, heirs also, heirs of God and fellow heirs with Christ, if indeed we suffer with Him in order that we may also be glorified with Him." (Romans 8:17)
"But when the fullness of the time came, God sent forth His Son, born of a woman, born under the Law, so that He might redeem those who were under the Law, that we might receive the adoption as sons." (Galatians 4:4-5)
Christ has possession over everything. We shall partake in His glory and riches as we have been included as members of the kingdom of heaven (John 17:22; 2 Corinthians 8:9). We are adopted as children of God in Christ:
"He predestined us to adoption as sons through Jesus Christ to Himself, according to the kind intention of His will." (Ephesians 1:5)
His shed blood brings about both our justification and adoption by God the Father. We belong to Him and He belongs to us.