Why did God emphasize that Jehovah is the one involved with the human race?
God emphasized Jehovah because once man entered the scene, humanity had to identify with its Creator, fellowship with Him, and know that He is. Jehovah is the Godhead person always involved with the human race: the communicator, Redeemer, Savior, and the one who fellowshipped with Adam and appeared to Abraham and Moses.
Les explains that the very name Jehovah refers to that person of the Godhead who is always involved with the human race. He is the communicator, the Redeemer, the Savior of mankind, the one who fellowships with Adam in the garden, and the one who appears to Abraham, Moses, and various others throughout the Old Testament. Les emphasizes this because man has now come into the scene, and God knows man must be able to identify with his Creator—not only fellowship with Him but know that He is. This is why God the Son is always Jehovah, with only one or two exceptions; when you see LORD in capital letters, it is Jehovah, God the Son.
These are the generations of the heavens and of the earth when they were created, in the day that the LORD God made the earth and the heavens,