During the time that man has lived on the earth, God has dealt with him in three different ways. For many years, He corresponded mainly with the heads of households. This is known as the Patriarchal Dispensation.
After the fall of Adam and Eve, God began working on His plan to send Jesus to save sinful man from his sins (Gen. 3:15). He selected Abram (later called Abraham), a man of faith to be a part of this plan. Even though Abraham had no children, God promised that he would become the father of many nations; that his descendants would be numberless as the sands of the sea; and that through his seed all families of the earth would be blessed (Gen. 12:1-3). (Jesus would be a human descendant of Abraham.)
God’s promise to Abraham was renewed to his son, Isaac and to his grandson, Jacob. Jacob’s name was changed to Israel and he became the father of the Israelite nation. The Israelites were chosen by God to be His special people through whom the Savior of the world would be born (Gen. 32:28; Is. 45:25).
After a long period of slavery in Egypt, God used Moses, an Israelite to lead His people into the Promised Land that He had promised to Abraham hundreds of years earlier (Ex. 3:7-10).
With a chosen nation with chosen people and with Moses as their leader, God instituted the Ten Commandments and related laws (Ex. 20:1-17). This is commonly referred to as the Law of Moses. This period of time became known as the Mosaic or Mosaical Dispensation. It remained in effect until the beginning of the present Christian Dispensation (Col. 2:13, 14).