Final answer:
God changed Abram's name to Abraham to signify a new purpose and identity for him, as well as to establish a covenant between them.
Step-by-step explanation:
The reason why God changed Abram's name to Abraham is because it represented a new purpose and identity for him. In the Hebrew tradition, names were given great significance and were often changed to reflect a change in status or destiny. Abram means "exalted father", while Abraham means "father of a multitude". By changing his name, God was signifying that He had chosen Abraham to be the father of many nations.
This change in name also represented a covenant (a sacred agreement) between God and Abraham. It symbolized God's promise to make Abraham the ancestor of a great nation and to bless him and his descendants. By changing his name, God was reinforcing this covenant and emphasizing the important role that Abraham would play in the history of the Hebrews.
Overall, the change in name from Abram to Abraham represented a new purpose and identity for Abraham, as well as a divine covenant between him and God.