US is referring to the Father (YHVH), Son (Yeshua), and Holy Spirit (Ruach HaKodesh) alone. Thus it writes, "YHVH is our God, YHVH alone." (Dt 6:4) When He said "they will become like us," recognize that God spoke many times in a mocking or sarcastic way. Thus it is written, "The One enthroned in heaven laughs; the Lord scoffs at them." (Ps 2:4) He laughs because it is an impossibility: "In the pride of your heart you say, 'I am a god; I sit on the throne of a god in the heart of the seas.' But you are a mere mortal and not a god, though you think you are as wise as a god." (Ez 28:2-3)