Final answer:
In Christian theology, the right to become children of God is given to those who believe in Jesus Christ as the Savior and the Son of God, as His sacrifice on the cross enables the possibility of eternal life in heaven.
Step-by-step explanation:
The student asked about the right to become children of God, specifically to those who believed in what. In Christian theology, this refers to believing in Jesus Christ as the Savior and the Son of God. This belief stems from the doctrine that Jesus' sacrifice on the cross allows human beings the possibility of eternal life in heaven, rectifying the original sin caused by Adam and Eve.
The New Testament, particularly the Gospel of John, often references 'believing in Jesus' as the requirement to become children of God. The passages provided in reference also suggest a broader inclusion of different peoples into the Christian faith, as highlighted by individuals like Saint Paul who argued that salvation was universally available to all, not just Jews.