The doctrine of the Trinity teaches that there is one God who eternally exists as three distinct persons: the Father, the Son (Jesus Christ), and the Holy Spirit. They are co-equal and co-eternal.

The Bible teaches that upon physical death, the souls of believers go immediately to be with Christ (Heaven), while the souls of non-believers are separated from God awaiting final judgment (Hell). There will be a future bodily resurrection for all.

66 books (39 in the Old Testament, 27 in the New Testament). Note: Catholic and Orthodox Bibles include additional books in the Old Testament, often called the Apocrypha or Deuterocanonical books, totaling 73 or more.

The Bible does not name Cain's wife. Based on the Genesis narrative, she must have been a descendant of Adam and Eve (a sister or niece) as they were the first and only human couple on earth at that time. Intermarriage was necessary for humanity to populate the earth.