Exodus 6:2-3 English Standard Version
2 God spoke to Moses and said to him, “I am the Lord. 3 I appeared to Abraham, to Isaac, and to Jacob, as God Almighty, but by my name the Lord I did not make myself known to them.
The Lord now appears before Moses to enact God Almighty’s promise. He promised Abram in Genesis 12:3 “him who dishonors you I will curse”. Now here in Exodus 6 God is appearing as Lord to carry out that promise.
Exodus 6:5-7 English Standard Version
5 Moreover, I have heard the groaning of the people of Israel whom the Egyptians hold as slaves, and I have remembered my covenant. 6 Say therefore to the people of Israel, ‘I am the Lord, and I will bring you out from under the burdens of the Egyptians, and I will deliver you from slavery to them, and I will redeem you with an outstretched arm and with great acts of judgment. 7 I will take you to be my people, and I will be your God, and you shall know that I am the Lord your God, who has brought you out from under the burdens of the Egyptians.
Abraham, Isaac and Jacob were not enslaved. There was no need to show Himself to them as the Lord who saves. The time had not come to enact His great promise of cursing those who had dishonored Abram. Now with great numbers of His people being dishonored, God chose Moses to be His voice to his people.
Verse 9 says “Moses spoke thus to the people of Israel, but they did not listen to Moses, because of their broken spirit and harsh slavery.”
Here is the key to our inclusion into this family of God. Like those slaves we had a broken spirit and were slaves to sin which was no longer pleasing. In this we should admit that the gospel message alone does not save us. It is only after He reveals Himself as Lord that we can leave with Him.