Again, I’m not a religious scholar by any stretch of the imagination, but your argument would essentially make Christian and Jewish beliefs as valid as Islam…if believing in one God and the Day of Judgment is all you need to believe, then why do we even need the Prophet Mohammed and Islam?
Personally I believe that according to Islam, righteous Christians/Jews/Zoroastrians all will be rewarded for their good deeds, but there still is a very clear distinction between them and believers/Muslims.
That isn’t the only verse dealing with the issue.
Again, the Quran specifically makes an exception for Muslim men marrying women from the people of the book: