Why are the Old Testament and the New Testament called testaments? A testament is a legal agreement, a pact, or a covenant. In this case, the whole Bible is a covenant that God made with His people, promising to save us through Christ. There is only one plan of salvation, and salvation has always been by grace through faith in Christ, but there are different ways that God expressed this covenant throughout history. When Jesus came, the changes in benefits were so striking that this expression was called a new covenant. Thus Christians began dividing the Bible into the old covenant and the new covenant, or the Old Testament and the New Testament.
