A name is more than just a means to call someone. In some cultures, the name of a person means their very identity and is indicative of not just what they are called, but who they are in essence.

Abram means Exalted Father and it was the name given to Abram, the husband of Sarai, by his father Terah.
Abraham means “Father of many nations” and it was the name given to Abram, by God himself.

Genesis 17:5-6 records the rechristening of Abram and starts by God telling Abram that he shall no longer be called Abram.
Note also how God tells Abraham that he shall not be the Father or One nation as was what he was promised earlier (Genesis 12:2), but now that he would the Father of many nations. God had told Abram he shall be the father of One nation, when he was still childless, but instead of trusting the Lord, he did not wait for the Lord’s timing. Now again, Abram is still childless, and God is telling him again that he would be the father of not one, but many nations. Abram had to trust in the Lord this time.

Hidden in this account are two spiritual Treasures. First, when we are rechristened by God, i.e., we  become a new creation (2 Corinthians 5:17), bearing the name of Jesus (Revelation 3:17; 1 Peter 4:14) and we should no longer be known by our previous names. In fact, name change requires a nature change … to trust in the Lord. Second, we see God magnanimity in blessing Abram not with just one nation, but with many nations.

Points to ponder:
Have you been rechristened by the Lord? i.e., have you believed in Jesus Christ? If you have, are your living by the name that you were given at birth or by the new name bearing the name of Jesus Christ? Has your name change resulted in your nature change? God is magnanimous is giving us more than than what we ask for or deserve.

Genesis 17:5-6 (KJV)
5 Neither shall thy name any more be called Abram, but thy name shall be Abraham; for a father of many nations have I made thee.